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The End.

C++ 对象的内存布局

2008-11-14 作者:陈皓 来源:csdn

前言

07年12月,我写了一篇《C++虚函数表解析》的文章,引起了大家的兴趣。有很多朋友对我的文章留了言,有鼓励我的,有批评我的,还有很多问问题的。我在这里一并对大家的留言表示感谢。这也是我为什么再写一篇续言的原因。因为,在上一篇文章中,我用了的示例都是非常简单的,主要是为了说明一些机理上的问题,也是为了图一些表达上方便和简单。不想,这篇文章成为了打开C++对象模型内存布局的一个引子,引发了大家对C++对象的更深层次的讨论。当然,我之前的文章还有很多方面没有涉及,从我个人感觉下来,在谈论虚函数表里,至少有以下这些内容没有涉及:

1)有成员变量的情况。

2)有重复继承的情况。

3)有虚拟继承的情况。

4)有钻石型虚拟继承的情况。

这些都是我本篇文章需要向大家说明的东西。所以,这篇文章将会是《C++虚函数表解析》的一个续篇,也是一篇高级进阶的文章。我希望大家在读这篇文章之前对C++有一定的基础和了解,并能先读我的上一篇文章。因为这篇文章的深度可能会比较深,而且会比较杂乱,我希望你在读本篇文章时不会有大脑思维紊乱导致大脑死机的情况。;-)

对象的影响因素

简而言之,我们一个类可能会有如下的影响因素:

1)成员变量

2)虚函数(产生虚函数表)

3)单一继承(只继承于一个类)

4)多重继承(继承多个类)

5)重复继承(继承的多个父类中其父类有相同的超类)

6)虚拟继承(使用virtual方式继承,为了保证继承后父类的内存布局只会存在一份)

上述的东西通常是C++这门语言在语义方面对对象内部的影响因素,当然,还会有编译器的影响(比如优化),还有字节对齐的影响。在这里我们都不讨论,我们只讨论C++语言上的影响。

本篇文章着重讨论下述几个情况下的C++对象的内存布局情况。

1)单一的一般继承(带成员变量、虚函数、虚函数覆盖)

2)单一的虚拟继承(带成员变量、虚函数、虚函数覆盖)

3)多重继承(带成员变量、虚函数、虚函数覆盖)

4)重复多重继承(带成员变量、虚函数、虚函数覆盖)

5)钻石型的虚拟多重继承(带成员变量、虚函数、虚函数覆盖)

我们的目标就是,让事情越来越复杂。

知识复习

我们简单地复习一下,我们可以通过对象的地址来取得虚函数表的地址,如:

   1: typedef void(*Fun)(void);
   2:  
   3: Base b;
   4:  
   5: Fun pFun = NULL;
   6:  
   7: cout << "虚函数表地址:" << (int*)(&b) << endl;
   8:  
   9: cout << "虚函数表 — 第一个函数地址:" << (int*)*(int*)(&b) << endl;
  10:  
  11: // Invoke the first virtual function 
  12:  
  13: pFun = (Fun)*((int*)*(int*)(&b));
  14:  
  15: pFun();
  16:  

  我们同样可以用这种方式来取得整个对象实例的内存布局。因为这些东西在内存中都是连续分布的,我们只需要使用适当的地址偏移量,我们就可以获得整个内存对象的布局。
</p>

<p>
  本篇文章中的例程或内存布局主要使用如下编译器和系统:
</p>

<p>
  1)Windows XP 和 VC++ 2003
</p>

<p>
  2)Cygwin 和 G++ 3.4.4
</p>

<p>
  <strong>单一的一般继承</strong>
</p>

<p>
  下面,我们假设有如下所示的一个继承关系:<br /> <br /><a href="/images/uploads/2010/04/dd0ssss11.jpg" rel="lightbox[983]"><img style="border-bottom: 0px; border-left: 0px; display: inline; border-top: 0px; border-right: 0px" title="dd0ssss1[1]" border="0" alt="dd0ssss1[1]" src="/images/uploads/2010/04/dd0ssss11_thumb.jpg" width="181" height="370" /></a>
</p>

<p>
</p>

<p>
  请注意,在这个继承关系中,父类,子类,孙子类都有自己的一个成员变量。而了类覆盖了父类的f()方法,孙子类覆盖了子类的g_child()及其超类的f()。
</p>

<p>
  我们的源程序如下所示:
</p>

<div>
  <div style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px">
    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   1:</span> <span style="color: #0000ff">class</span> Parent {</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   2:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   3:</span> <span style="color: #0000ff">public</span>:</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   4:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   5:</span> <span style="color: #0000ff">int</span> iparent;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   6:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   7:</span> Parent ():iparent (10) {}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   8:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   9:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> f() { cout &lt;&lt; <span style="color: #006080">" Parent::f()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  10:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  11:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> g() { cout &lt;&lt; <span style="color: #006080">" Parent::g()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  12:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  13:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> h() { cout &lt;&lt; <span style="color: #006080">" Parent::h()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  14:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  15:</span>  </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  16:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  17:</span> };</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  18:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  19:</span>  </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  20:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  21:</span> <span style="color: #0000ff">class</span> Child : <span style="color: #0000ff">public</span> Parent {</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  22:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  23:</span> <span style="color: #0000ff">public</span>:</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  24:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  25:</span> <span style="color: #0000ff">int</span> ichild;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  26:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  27:</span> Child():ichild(100) {}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  28:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  29:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> f() { cout &lt;&lt; <span style="color: #006080">"Child::f()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  30:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  31:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> g_child() { cout &lt;&lt; <span style="color: #006080">"Child::g_child()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  32:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  33:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> h_child() { cout &lt;&lt; <span style="color: #006080">"Child::h_child()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  34:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  35:</span> };</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  36:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  37:</span>  </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  38:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  39:</span> <span style="color: #0000ff">class</span> GrandChild : <span style="color: #0000ff">public</span> Child{</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  40:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  41:</span> <span style="color: #0000ff">public</span>:</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  42:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  43:</span> <span style="color: #0000ff">int</span> igrandchild;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  44:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  45:</span> GrandChild():igrandchild(1000) {}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  46:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  47:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> f() { cout &lt;&lt; <span style="color: #006080">"GrandChild::f()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  48:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  49:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> g_child() { cout &lt;&lt; <span style="color: #006080">"GrandChild::g_child()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  50:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  51:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> h_grandchild() { cout &lt;&lt; <span style="color: #006080">"GrandChild::h_grandchild()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  52:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  53:</span> };</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  54:</span>&#160; </pre></p>
  </div>
</div>

<p>
  我们使用以下程序作为测试程序:(下面程序中,我使用了一个int** pVtab 来作为遍历对象内存布局的指针,这样,我就可以方便地像使用数组一样来遍历所有的成员包括其虚函数表了,在后面的程序中,我也是用这样的方法的,请不必感到奇怪,)
</p>

<p>
</p>

<div>
  <div style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px">
    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   1:</span> typedef <span style="color: #0000ff">void</span>(*Fun)(<span style="color: #0000ff">void</span>);</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   2:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   3:</span> GrandChild gc; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   4:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   5:</span> <span style="color: #0000ff">int</span>** pVtab = (<span style="color: #0000ff">int</span>**)&gc;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   6:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   7:</span> cout &lt;&lt; <span style="color: #006080">"[0] GrandChild::_vptr-&gt;"</span> &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   8:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   9:</span> <span style="color: #0000ff">for</span> (<span style="color: #0000ff">int</span> i=0; (Fun)pVtab[0][i]!=NULL; i++){</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  10:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  11:</span> pFun = (Fun)pVtab[0][i];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  12:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  13:</span> cout &lt;&lt; <span style="color: #006080">" ["</span>&lt;&lt;i&lt;&lt;<span style="color: #006080">"] "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  14:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  15:</span> pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  16:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  17:</span> }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  18:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  19:</span> cout &lt;&lt; <span style="color: #006080">"[1] Parent.iparent = "</span> &lt;&lt; (<span style="color: #0000ff">int</span>)pVtab[1] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  20:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  21:</span> cout &lt;&lt; <span style="color: #006080">"[2] Child.ichild = "</span> &lt;&lt; (<span style="color: #0000ff">int</span>)pVtab[2] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  22:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  23:</span> cout &lt;&lt; <span style="color: #006080">"[3] GrandChild.igrandchild = "</span> &lt;&lt; (<span style="color: #0000ff">int</span>)pVtab[3] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  24:</span>&#160; </pre></p>
  </div>
</div>

<p>
  其运行结果如下所示:(在VC++ 2003和G++ 3.4.4下)
</p>

<p>
  <a href="/images/uploads/2010/04/image2.png" rel="lightbox[983]"><img style="border-bottom: 0px; border-left: 0px; display: inline; border-top: 0px; border-right: 0px" title="image" border="0" alt="image" src="/images/uploads/2010/04/image_thumb.png" width="438" height="165" /></a>
</p>

<p>
  使用图片表示如下:
</p>

<p>
  <a href="/images/uploads/2010/04/ddsssssss021.jpg" rel="lightbox[983]"><img style="border-bottom: 0px; border-left: 0px; display: inline; border-top: 0px; border-right: 0px" title="ddsssssss02[1]" border="0" alt="ddsssssss02[1]" src="/images/uploads/2010/04/ddsssssss021_thumb.jpg" width="504" height="241" /></a>
</p>

<p>
  可见以下几个方面:
</p>

<p>
  1)虚函数表在最前面的位置。
</p>

<p>
  2)成员变量根据其继承和声明顺序依次放在后面。
</p>

<p>
  3)在单一的继承中,被overwrite的虚函数在虚函数表中得到了更新。
</p>

<p>
  <strong>多重继承</strong>
</p>

<p>
  下面,再让我们来看看多重继承中的情况,假设有下面这样一个类的继承关系。注意:子类只overwrite了父类的f()函数,而还有一个是自己的函数(我们这样做的目的是为了用g1()作为一个标记来标明子类的虚函数表)。而且每个类中都有一个自己的成员变量:
</p>

<p>
  <a href="/images/uploads/2010/04/dd031.jpg" rel="lightbox[983]"><img style="border-bottom: 0px; border-left: 0px; display: inline; border-top: 0px; border-right: 0px" title="dd03[1]" border="0" alt="dd03[1]" src="/images/uploads/2010/04/dd031_thumb.jpg" width="332" height="269" /></a>
</p>

<p>
  我们的类继承的源代码如下所示:父类的成员初始为10,20,30,子类的为100
</p>

<p>
</p>

<div>
  <div style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px">
    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   1:</span> <span style="color: #0000ff">class</span> Base1 {</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   2:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   3:</span> <span style="color: #0000ff">public</span>:</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   4:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   5:</span> <span style="color: #0000ff">int</span> ibase1;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   6:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   7:</span> Base1():ibase1(10) {}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   8:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   9:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> f() { cout &lt;&lt; <span style="color: #006080">"Base1::f()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  10:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  11:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> g() { cout &lt;&lt; <span style="color: #006080">"Base1::g()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  12:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  13:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> h() { cout &lt;&lt; <span style="color: #006080">"Base1::h()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  14:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  15:</span>  </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  16:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  17:</span> };</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  18:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  19:</span> <span style="color: #0000ff">class</span> Base2 {</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  20:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  21:</span> <span style="color: #0000ff">public</span>:</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  22:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  23:</span> <span style="color: #0000ff">int</span> ibase2;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  24:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  25:</span> Base2():ibase2(20) {}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  26:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  27:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> f() { cout &lt;&lt; <span style="color: #006080">"Base2::f()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  28:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  29:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> g() { cout &lt;&lt; <span style="color: #006080">"Base2::g()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  30:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  31:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> h() { cout &lt;&lt; <span style="color: #006080">"Base2::h()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  32:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  33:</span> };</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  34:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  35:</span> <span style="color: #0000ff">class</span> Base3 {</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  36:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  37:</span> <span style="color: #0000ff">public</span>:</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  38:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  39:</span> <span style="color: #0000ff">int</span> ibase3;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  40:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  41:</span> Base3():ibase3(30) {}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  42:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  43:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> f() { cout &lt;&lt; <span style="color: #006080">"Base3::f()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  44:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  45:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> g() { cout &lt;&lt; <span style="color: #006080">"Base3::g()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  46:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  47:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> h() { cout &lt;&lt; <span style="color: #006080">"Base3::h()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  48:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  49:</span> };</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  50:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  51:</span> <span style="color: #0000ff">class</span> Derive : <span style="color: #0000ff">public</span> Base1, <span style="color: #0000ff">public</span> Base2, <span style="color: #0000ff">public</span> Base3 {</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  52:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  53:</span> <span style="color: #0000ff">public</span>:</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  54:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  55:</span> <span style="color: #0000ff">int</span> iderive;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  56:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  57:</span> Derive():iderive(100) {}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  58:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  59:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> f() { cout &lt;&lt; <span style="color: #006080">"Derive::f()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  60:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  61:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> g1() { cout &lt;&lt; <span style="color: #006080">"Derive::g1()"</span> &lt;&lt; endl; }</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  62:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  63:</span> };</pre></p>
  </div>
</div>

<p>
  我们通过下面的程序来查看子类实例的内存布局:下面程序中,注意我使用了一个s变量,其中用到了sizof(Base)来找下一个类的偏移量。(因为我声明的是int成员,所以是4个字节,所以没有对齐问题。关于内存的对齐问题,大家可以自行试验,我在这里就不多说了)
</p>

<p>
</p>

<div>
  <div style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px">
    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   1:</span> typedef <span style="color: #0000ff">void</span>(*Fun)(<span style="color: #0000ff">void</span>);</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   2:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   3:</span> Derive d;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   4:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   5:</span> <span style="color: #0000ff">int</span>** pVtab = (<span style="color: #0000ff">int</span>**)&d;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   6:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   7:</span> cout &lt;&lt; <span style="color: #006080">"[0] Base1::_vptr-&gt;"</span> &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   8:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   9:</span> pFun = (Fun)pVtab[0][0];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  10:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  11:</span> cout &lt;&lt; <span style="color: #006080">" [0] "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  12:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  13:</span> pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  14:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  15:</span> pFun = (Fun)pVtab[0][1];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  16:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  17:</span> cout &lt;&lt; <span style="color: #006080">" [1] "</span>;pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  18:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  19:</span> pFun = (Fun)pVtab[0][2];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  20:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  21:</span> cout &lt;&lt; <span style="color: #006080">" [2] "</span>;pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  22:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  23:</span> pFun = (Fun)pVtab[0][3];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  24:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  25:</span> cout &lt;&lt; <span style="color: #006080">" [3] "</span>; pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  26:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  27:</span> pFun = (Fun)pVtab[0][4];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  28:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  29:</span> cout &lt;&lt; <span style="color: #006080">" [4] "</span>; cout&lt;&lt;pFun&lt;&lt;endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  30:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  31:</span> cout &lt;&lt; <span style="color: #006080">"[1] Base1.ibase1 = "</span> &lt;&lt; (<span style="color: #0000ff">int</span>)pVtab[1] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  32:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  33:</span> <span style="color: #0000ff">int</span> s = <span style="color: #0000ff">sizeof</span>(Base1)/4;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  34:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  35:</span> cout &lt;&lt; <span style="color: #006080">"["</span> &lt;&lt; s &lt;&lt; <span style="color: #006080">"] Base2::_vptr-&gt;"</span>&lt;&lt;endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  36:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  37:</span> pFun = (Fun)pVtab[s][0];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  38:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  39:</span> cout &lt;&lt; <span style="color: #006080">" [0] "</span>; pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  40:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  41:</span> Fun = (Fun)pVtab[s][1];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  42:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  43:</span> cout &lt;&lt; <span style="color: #006080">" [1] "</span>; pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  44:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  45:</span> pFun = (Fun)pVtab[s][2];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  46:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  47:</span> cout &lt;&lt; <span style="color: #006080">" [2] "</span>; pFun(); </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  48:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  49:</span> pFun = (Fun)pVtab[s][3];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  50:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  51:</span> <span style="color: #0000ff">out</span> &lt;&lt; <span style="color: #006080">" [3] "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  52:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  53:</span> cout&lt;&lt;pFun&lt;&lt;endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  54:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  55:</span> cout &lt;&lt; <span style="color: #006080">"["</span>&lt;&lt; s+1 &lt;&lt;<span style="color: #006080">"] Base2.ibase2 = "</span> &lt;&lt; (<span style="color: #0000ff">int</span>)pVtab[s+1] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  56:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  57:</span> s = s + <span style="color: #0000ff">sizeof</span>(Base2)/4;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  58:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  59:</span> cout &lt;&lt; <span style="color: #006080">"["</span> &lt;&lt; s &lt;&lt; <span style="color: #006080">"] Base3::_vptr-&gt;"</span>&lt;&lt;endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  60:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  61:</span> pFun = (Fun)pVtab[s][0];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  62:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  63:</span> cout &lt;&lt; <span style="color: #006080">" [0] "</span>; pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  64:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  65:</span>  </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  66:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  67:</span> pFun = (Fun)pVtab[s][1];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  68:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  69:</span> cout &lt;&lt; <span style="color: #006080">" [1] "</span>; pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  70:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  71:</span> pFun = (Fun)pVtab[s][2];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  72:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  73:</span> cout &lt;&lt; <span style="color: #006080">" [2] "</span>; pFun(); </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  74:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  75:</span>  </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  76:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  77:</span> pFun = (Fun)pVtab[s][3];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  78:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  79:</span> cout &lt;&lt; <span style="color: #006080">" [3] "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  80:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  81:</span> cout&lt;&lt;pFun&lt;&lt;endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  82:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  83:</span> s++;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  84:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  85:</span> cout &lt;&lt; <span style="color: #006080">"["</span>&lt;&lt; s &lt;&lt;<span style="color: #006080">"] Base3.ibase3 = "</span> &lt;&lt; (<span style="color: #0000ff">int</span>)pVtab[s] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  86:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  87:</span> s++;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  88:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  89:</span> cout &lt;&lt; <span style="color: #006080">"["</span>&lt;&lt; s &lt;&lt;<span style="color: #006080">"] Derive.iderive = "</span> &lt;&lt; (<span style="color: #0000ff">int</span>)pVtab[s] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  90:</span>&#160; </pre></p>
  </div>
</div>

<p>
  其运行结果如下所示:(在VC++ 2003和G++ 3.4.4下)
</p>

<p>
  <a href="/images/uploads/2010/04/image3.png" rel="lightbox[983]"><img style="border-bottom: 0px; border-left: 0px; display: inline; border-top: 0px; border-right: 0px" title="image" border="0" alt="image" src="/images/uploads/2010/04/image_thumb1.png" width="452" height="325" /></a>
</p>

<p>
  使用图片表示是下面这个样子:<br /> <br /><a href="/images/uploads/2010/04/dd041.jpg" rel="lightbox[983]"><img style="border-bottom: 0px; border-left: 0px; display: inline; border-top: 0px; border-right: 0px" title="dd04[1]" border="0" alt="dd04[1]" src="/images/uploads/2010/04/dd041_thumb.jpg" width="504" height="291" /></a>
</p>

<p>
</p>

<p>
  我们可以看到:
</p>

<p>
  1) 每个父类都有自己的虚表。
</p>

<p>
  2) 子类的成员函数被放到了第一个父类的表中。
</p>

<p>
  3) 内存布局中,其父类布局依次按声明顺序排列。
</p>

<p>
  4) 每个父类的虚表中的f()函数都被overwrite成了子类的f()。这样做就是为了解决不同的父类类型的指针指向同一个子类实例,而能够调用到实际的函数。
</p>

<p>
  <strong>重复继承</strong>
</p>

<p>
  下面我们再来看看,发生重复继承的情况。所谓重复继承,也就是某个基类被间接地重复继承了多次。
</p>

<p>
  下图是一个继承图,我们重载了父类的f()函数。
</p>

<p>
  <a href="/images/uploads/2010/04/dd051.jpg" rel="lightbox[983]"><img style="border-bottom: 0px; border-left: 0px; display: inline; border-top: 0px; border-right: 0px" title="dd05[1]" border="0" alt="dd05[1]" src="/images/uploads/2010/04/dd051_thumb.jpg" width="257" height="397" /></a>
</p>

<p>
  其类继承的源代码如下所示。其中,每个类都有两个变量,一个是整形(4字节),一个是字符(1字节),而且还有自己的虚函数,自己overwrite父类的虚函数。如子类D中,f()覆盖了超类的函数, f1() 和f2() 覆盖了其父类的虚函数,Df()为自己的虚函数。
</p>

<p>
</p>

<div>
  <div style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px">
    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   1:</span> <span style="color: #0000ff">class</span> B</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   2:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   3:</span> {</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   4:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   5:</span> <span style="color: #0000ff">public</span>:</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   6:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   7:</span> <span style="color: #0000ff">int</span> ib;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   8:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   9:</span> <span style="color: #0000ff">char</span> cb;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  10:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  11:</span> <span style="color: #0000ff">public</span>:</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  12:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  13:</span> B():ib(0),cb(<span style="color: #006080">'B'</span>) {}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  14:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  15:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> f() { cout &lt;&lt; <span style="color: #006080">"B::f()"</span> &lt;&lt; endl;}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  16:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  17:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> Bf() { cout &lt;&lt; <span style="color: #006080">"B::Bf()"</span> &lt;&lt; endl;}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  18:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  19:</span> };</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  20:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  21:</span> <span style="color: #0000ff">class</span> B1 : <span style="color: #0000ff">public</span> B</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  22:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  23:</span> {</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  24:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  25:</span> <span style="color: #0000ff">public</span>:</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  26:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  27:</span> <span style="color: #0000ff">int</span> ib1;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  28:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  29:</span> <span style="color: #0000ff">char</span> cb1;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  30:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  31:</span> <span style="color: #0000ff">public</span>:</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  32:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  33:</span> B1():ib1(11),cb1(<span style="color: #006080">'1'</span>) {}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  34:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  35:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> f() { cout &lt;&lt; <span style="color: #006080">"B1::f()"</span> &lt;&lt; endl;}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  36:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  37:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> f1() { cout &lt;&lt; <span style="color: #006080">"B1::f1()"</span> &lt;&lt; endl;}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  38:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  39:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> Bf1() { cout &lt;&lt; <span style="color: #006080">"B1::Bf1()"</span> &lt;&lt; endl;}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  40:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  41:</span> };</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  42:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  43:</span> <span style="color: #0000ff">class</span> B2: <span style="color: #0000ff">public</span> B</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  44:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  45:</span> {</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  46:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  47:</span> <span style="color: #0000ff">public</span>:</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  48:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  49:</span> <span style="color: #0000ff">int</span> ib2;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  50:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  51:</span> <span style="color: #0000ff">char</span> cb2;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  52:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  53:</span> <span style="color: #0000ff">public</span>:</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  54:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  55:</span> B2():ib2(12),cb2(<span style="color: #006080">'2'</span>) {}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  56:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  57:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> f() { cout &lt;&lt; <span style="color: #006080">"B2::f()"</span> &lt;&lt; endl;}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  58:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  59:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> f2() { cout &lt;&lt; <span style="color: #006080">"B2::f2()"</span> &lt;&lt; endl;}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  60:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  61:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> Bf2() { cout &lt;&lt; <span style="color: #006080">"B2::Bf2()"</span> &lt;&lt; endl;}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  62:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  63:</span> };</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  64:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  65:</span> <span style="color: #0000ff">class</span> D : <span style="color: #0000ff">public</span> B1, <span style="color: #0000ff">public</span> B2</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  66:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  67:</span> {</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  68:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  69:</span> <span style="color: #0000ff">public</span>:</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  70:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  71:</span> <span style="color: #0000ff">int</span> id;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  72:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  73:</span> <span style="color: #0000ff">char</span> cd;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  74:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  75:</span> <span style="color: #0000ff">public</span>:</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  76:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  77:</span> D():id(100),cd(<span style="color: #006080">'D'</span>) {}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  78:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  79:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> f() { cout &lt;&lt; <span style="color: #006080">"D::f()"</span> &lt;&lt; endl;}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  80:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  81:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> f1() { cout &lt;&lt; <span style="color: #006080">"D::f1()"</span> &lt;&lt; endl;}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  82:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  83:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> f2() { cout &lt;&lt; <span style="color: #006080">"D::f2()"</span> &lt;&lt; endl;}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  84:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  85:</span> <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">void</span> Df() { cout &lt;&lt; <span style="color: #006080">"D::Df()"</span> &lt;&lt; endl;}</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  86:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  87:</span> };</pre></p>
  </div>
</div>

<p>
  我们用来存取子类内存布局的代码如下所示:(在VC++ 2003和G++ 3.4.4下)<br />
</p>

<div>
  <div style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px">
    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   1:</span> typedef <span style="color: #0000ff">void</span>(*Fun)(<span style="color: #0000ff">void</span>);</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   2:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   3:</span> <span style="color: #0000ff">int</span>** pVtab = NULL;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   4:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   5:</span> Fun pFun = NULL;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   6:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   7:</span> D d;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   8:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   9:</span> pVtab = (<span style="color: #0000ff">int</span>**)&d;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  10:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  11:</span> cout &lt;&lt; <span style="color: #006080">"[0] D::B1::_vptr-&gt;"</span> &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  12:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  13:</span> pFun = (Fun)pVtab[0][0];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  14:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  15:</span> cout &lt;&lt; <span style="color: #006080">" [0] "</span>; pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  16:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  17:</span> pFun = (Fun)pVtab[0][1];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  18:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  19:</span> cout &lt;&lt; <span style="color: #006080">" [1] "</span>; pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  20:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  21:</span> pFun = (Fun)pVtab[0][2];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  22:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  23:</span> cout &lt;&lt; <span style="color: #006080">" [2] "</span>; pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  24:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  25:</span> pFun = (Fun)pVtab[0][3];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  26:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  27:</span> cout &lt;&lt; <span style="color: #006080">" [3] "</span>; pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  28:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  29:</span> pFun = (Fun)pVtab[0][4];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  30:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  31:</span> cout &lt;&lt; <span style="color: #006080">" [4] "</span>; pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  32:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  33:</span> pFun = (Fun)pVtab[0][5];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  34:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  35:</span> cout &lt;&lt; <span style="color: #006080">" [5] 0x"</span> &lt;&lt; pFun &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  36:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  37:</span> cout &lt;&lt; <span style="color: #006080">"[1] B::ib = "</span> &lt;&lt; (<span style="color: #0000ff">int</span>)pVtab[1] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  38:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  39:</span> cout &lt;&lt; <span style="color: #006080">"[2] B::cb = "</span> &lt;&lt; (<span style="color: #0000ff">char</span>)pVtab[2] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  40:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  41:</span> cout &lt;&lt; <span style="color: #006080">"[3] B1::ib1 = "</span> &lt;&lt; (<span style="color: #0000ff">int</span>)pVtab[3] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  42:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  43:</span> cout &lt;&lt; <span style="color: #006080">"[4] B1::cb1 = "</span> &lt;&lt; (<span style="color: #0000ff">char</span>)pVtab[4] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  44:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  45:</span> cout &lt;&lt; <span style="color: #006080">"[5] D::B2::_vptr-&gt;"</span> &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  46:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  47:</span> pFun = (Fun)pVtab[5][0];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  48:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  49:</span> cout &lt;&lt; <span style="color: #006080">" [0] "</span>; pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  50:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  51:</span> pFun = (Fun)pVtab[5][1];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  52:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  53:</span> cout &lt;&lt; <span style="color: #006080">" [1] "</span>; pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  54:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  55:</span> pFun = (Fun)pVtab[5][2];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  56:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  57:</span> cout &lt;&lt; <span style="color: #006080">" [2] "</span>; pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  58:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  59:</span> pFun = (Fun)pVtab[5][3];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  60:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  61:</span> cout &lt;&lt; <span style="color: #006080">" [3] "</span>; pFun();</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  62:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  63:</span> pFun = (Fun)pVtab[5][4];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  64:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  65:</span> cout &lt;&lt; <span style="color: #006080">" [4] 0x"</span> &lt;&lt; pFun &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  66:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  67:</span> cout &lt;&lt; <span style="color: #006080">"[6] B::ib = "</span> &lt;&lt; (<span style="color: #0000ff">int</span>)pVtab[6] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  68:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  69:</span> cout &lt;&lt; <span style="color: #006080">"[7] B::cb = "</span> &lt;&lt; (<span style="color: #0000ff">char</span>)pVtab[7] &lt;&lt; endl; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  70:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  71:</span> cout &lt;&lt; <span style="color: #006080">"[8] B2::ib2 = "</span> &lt;&lt; (<span style="color: #0000ff">int</span>)pVtab[8] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  72:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  73:</span> cout &lt;&lt; <span style="color: #006080">"[9] B2::cb2 = "</span> &lt;&lt; (<span style="color: #0000ff">char</span>)pVtab[9] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  74:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  75:</span> cout &lt;&lt; <span style="color: #006080">"[10] D::id = "</span> &lt;&lt; (<span style="color: #0000ff">int</span>)pVtab[10] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  76:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  77:</span> cout &lt;&lt; <span style="color: #006080">"[11] D::cd = "</span> &lt;&lt; (<span style="color: #0000ff">char</span>)pVtab[11] &lt;&lt; endl;</pre></p>
  </div>
</div>

<p>
  程序运行结果如下:
</p>

<p>
  <a href="/images/uploads/2010/04/image4.png" rel="lightbox[983]"><img style="border-bottom: 0px; border-left: 0px; display: inline; border-top: 0px; border-right: 0px" title="image" border="0" alt="image" src="/images/uploads/2010/04/image_thumb2.png" width="569" height="403" /></a>
</p>

<p>
  下面是对于子类实例中的虚函数表的图:
</p>

<p>
  <a href="/images/uploads/2010/04/dd061.jpg" rel="lightbox[983]"><img style="border-bottom: 0px; border-left: 0px; display: inline; border-top: 0px; border-right: 0px" title="dd06[1]" border="0" alt="dd06[1]" src="/images/uploads/2010/04/dd061_thumb.jpg" width="404" height="309" /></a>
</p>

<p>
  我们可以看见,最顶端的父类B其成员变量存在于B1和B2中,并被D给继承下去了。而在D中,其有B1和B2的实例,于是B的成员在D的实例中存在两份,一份是B1继承而来的,另一份是B2继承而来的。所以,如果我们使用以下语句,则会产生二义性编译错误:
</p>

<p>
</p>

<div>
  <div style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px">
    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   1:</span> D d;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   2:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   3:</span> d.ib = 0; <span style="color: #008000">//二义性错误</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   4:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   5:</span> d.B1::ib = 1; <span style="color: #008000">//正确</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   6:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   7:</span> d.B2::ib = 2; <span style="color: #008000">//正确</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   8:</span>&#160; </pre></p>
  </div>
</div>

<p>
  注意,上面例程中的最后两条语句存取的是两个变量。虽然我们消除了二义性的编译错误,但B类在D中还是有两个实例,这种继承造成了数据的重复,我们叫这种继承为重复继承。重复的基类数据成员可能并不是我们想要的。所以,C++引入了虚基类的概念。
</p>

<p>
  <strong>钻石型多重虚拟继承</strong>
</p>

<p>
  虚拟继承的出现就是为了解决重复继承中多个间接父类的问题的。钻石型的结构是其最经典的结构。也是我们在这里要讨论的结构:
</p>

<p>
  上述的“重复继承”只需要把B1和B2继承B的语法中加上virtual 关键,就成了虚拟继承,其继承图如下所示:
</p>

<p>
  <a href="/images/uploads/2010/04/dd071.jpg" rel="lightbox[983]"><img style="border-bottom: 0px; border-left: 0px; display: inline; border-top: 0px; border-right: 0px" title="dd07[1]" border="0" alt="dd07[1]" src="/images/uploads/2010/04/dd071_thumb.jpg" width="257" height="408" /></a>
</p>

<p>
  上图和前面的“重复继承”中的类的内部数据和接口都是完全一样的,只是我们采用了虚拟继承:其省略后的源码如下所示:
</p>

<p>
</p>

<div>
  <div style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px">
    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   1:</span> <span style="color: #0000ff">class</span> B {……};</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   2:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   3:</span> <span style="color: #0000ff">class</span> B1 : <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">public</span> B{……};</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   4:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   5:</span> <span style="color: #0000ff">class</span> B2: <span style="color: #0000ff">virtual</span> <span style="color: #0000ff">public</span> B{……};</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   6:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   7:</span> <span style="color: #0000ff">class</span> D : <span style="color: #0000ff">public</span> B1, <span style="color: #0000ff">public</span> B2{ …… };</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   8:</span>&#160; </pre></p>
  </div>
</div>

<p>
  在查看D之前,我们先看一看单一虚拟继承的情况。下面是一段在VC++2003下的测试程序:(因为VC++和GCC的内存而局上有一些细节上的不同,所以这里只给出VC++的程序,GCC下的程序大家可以根据我给出的程序自己仿照着写一个去试一试):
</p>

<p>
</p>

<div>
  <div style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px">
    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   1:</span> <span style="color: #0000ff">int</span>** pVtab = NULL;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   2:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   3:</span> Fun pFun = NULL;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   4:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   5:</span>  </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   6:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   7:</span> B1 bb1;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   8:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   9:</span> pVtab = (<span style="color: #0000ff">int</span>**)&bb1;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  10:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  11:</span> cout &lt;&lt; <span style="color: #006080">"[0] B1::_vptr-&gt;"</span> &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  12:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  13:</span> pFun = (Fun)pVtab[0][0];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  14:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  15:</span> cout &lt;&lt; <span style="color: #006080">" [0] "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  16:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  17:</span> pFun(); <span style="color: #008000">//B1::f1();</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  18:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  19:</span> cout &lt;&lt; <span style="color: #006080">" [1] "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  20:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  21:</span> pFun = (Fun)pVtab[0][1];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  22:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  23:</span> pFun(); <span style="color: #008000">//B1::bf1();</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  24:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  25:</span> cout &lt;&lt; <span style="color: #006080">" [2] "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  26:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  27:</span> cout &lt;&lt; pVtab[0][2] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  28:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  29:</span> cout &lt;&lt; <span style="color: #006080">"[1] = 0x"</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  30:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  31:</span> cout &lt;&lt; (<span style="color: #0000ff">int</span>*)*((<span style="color: #0000ff">int</span>*)(&bb1)+1) &lt;&lt;endl; <span style="color: #008000">//B1::ib1</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  32:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  33:</span> cout &lt;&lt; <span style="color: #006080">"[2] B1::ib1 = "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  34:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  35:</span> cout &lt;&lt; (<span style="color: #0000ff">int</span>)*((<span style="color: #0000ff">int</span>*)(&bb1)+2) &lt;&lt;endl; <span style="color: #008000">//B1::ib1</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  36:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  37:</span> cout &lt;&lt; <span style="color: #006080">"[3] B1::cb1 = "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  38:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  39:</span> cout &lt;&lt; (<span style="color: #0000ff">char</span>)*((<span style="color: #0000ff">int</span>*)(&bb1)+3) &lt;&lt; endl; <span style="color: #008000">//B1::cb1</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  40:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  41:</span> cout &lt;&lt; <span style="color: #006080">"[4] = 0x"</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  42:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  43:</span> cout &lt;&lt; (<span style="color: #0000ff">int</span>*)*((<span style="color: #0000ff">int</span>*)(&bb1)+4) &lt;&lt; endl; <span style="color: #008000">//NULL</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  44:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  45:</span> cout &lt;&lt; <span style="color: #006080">"[5] B::_vptr-&gt;"</span> &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  46:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  47:</span> pFun = (Fun)pVtab[5][0];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  48:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  49:</span> cout &lt;&lt; <span style="color: #006080">" [0] "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  50:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  51:</span> pFun(); <span style="color: #008000">//B1::f();</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  52:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  53:</span> pFun = (Fun)pVtab[5][1];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  54:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  55:</span> cout &lt;&lt; <span style="color: #006080">" [1] "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  56:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  57:</span> pFun(); <span style="color: #008000">//B::Bf();</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  58:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  59:</span> cout &lt;&lt; <span style="color: #006080">" [2] "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  60:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  61:</span> cout &lt;&lt; <span style="color: #006080">"0x"</span> &lt;&lt; (Fun)pVtab[5][2] &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  62:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  63:</span> cout &lt;&lt; <span style="color: #006080">"[6] B::ib = "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  64:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  65:</span> cout &lt;&lt; (<span style="color: #0000ff">int</span>)*((<span style="color: #0000ff">int</span>*)(&bb1)+6) &lt;&lt;endl; <span style="color: #008000">//B::ib</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  66:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  67:</span> cout &lt;&lt; <span style="color: #006080">"[7] B::cb = "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  68:</span>&#160; </pre></p>
  </div>
</div>

<p>
  其运行结果如下(我结出了GCC的和VC++2003的对比):
</p>

<p>
  <a href="/images/uploads/2010/04/image5.png" rel="lightbox[983]"><img style="border-bottom: 0px; border-left: 0px; display: inline; border-top: 0px; border-right: 0px" title="image" border="0" alt="image" src="/images/uploads/2010/04/image_thumb3.png" width="623" height="247" /></a>
</p>

<p>
  这里,大家可以自己对比一下。关于细节上,我会在后面一并再说。
</p>

<p>
  下面的测试程序是看子类D的内存布局,同样是VC++ 2003的(因为VC++和GCC的内存布局上有一些细节上的不同,而VC++的相对要清楚很多,所以这里只给出VC++的程序,GCC下的程序大家可以根据我给出的程序自己仿照着写一个去试一试):
</p>

<p>
</p>

<div>
  <div style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px">
    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   1:</span> D d;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   2:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   3:</span> pVtab = (<span style="color: #0000ff">int</span>**)&d;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   4:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   5:</span> cout &lt;&lt; <span style="color: #006080">"[0] D::B1::_vptr-&gt;"</span> &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   6:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   7:</span> pFun = (Fun)pVtab[0][0];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   8:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">   9:</span> cout &lt;&lt; <span style="color: #006080">" [0] "</span>; pFun(); <span style="color: #008000">//D::f1();</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  10:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  11:</span> pFun = (Fun)pVtab[0][1];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  12:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  13:</span> cout &lt;&lt; <span style="color: #006080">" [1] "</span>; pFun(); <span style="color: #008000">//B1::Bf1();</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  14:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  15:</span> pFun = (Fun)pVtab[0][2];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  16:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  17:</span> cout &lt;&lt; <span style="color: #006080">" [2] "</span>; pFun(); <span style="color: #008000">//D::Df();</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  18:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  19:</span> pFun = (Fun)pVtab[0][3];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  20:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  21:</span> cout &lt;&lt; <span style="color: #006080">" [3] "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  22:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  23:</span> cout &lt;&lt; pFun &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  24:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  25:</span> <span style="color: #008000">//cout &lt;&lt; pVtab[4][2] &lt;&lt; endl;</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  26:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  27:</span> cout &lt;&lt; <span style="color: #006080">"[1] = 0x"</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  28:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  29:</span> cout &lt;&lt; (<span style="color: #0000ff">int</span>*)((&dd)+1) &lt;&lt;endl; <span style="color: #008000">//????</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  30:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  31:</span> cout &lt;&lt; <span style="color: #006080">"[2] B1::ib1 = "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  32:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  33:</span> cout &lt;&lt; *((<span style="color: #0000ff">int</span>*)(&dd)+2) &lt;&lt;endl; <span style="color: #008000">//B1::ib1</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  34:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  35:</span> cout &lt;&lt; <span style="color: #006080">"[3] B1::cb1 = "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  36:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  37:</span> cout &lt;&lt; (<span style="color: #0000ff">char</span>)*((<span style="color: #0000ff">int</span>*)(&dd)+3) &lt;&lt; endl; <span style="color: #008000">//B1::cb1</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  38:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  39:</span> <span style="color: #008000">//---------------------</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  40:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  41:</span> cout &lt;&lt; <span style="color: #006080">"[4] D::B2::_vptr-&gt;"</span> &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  42:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  43:</span> pFun = (Fun)pVtab[4][0];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  44:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  45:</span> cout &lt;&lt; <span style="color: #006080">" [0] "</span>; pFun(); <span style="color: #008000">//D::f2();</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  46:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  47:</span> pFun = (Fun)pVtab[4][1];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  48:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  49:</span> cout &lt;&lt; <span style="color: #006080">" [1] "</span>; pFun(); <span style="color: #008000">//B2::Bf2();</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  50:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  51:</span> pFun = (Fun)pVtab[4][2];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  52:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  53:</span> cout &lt;&lt; <span style="color: #006080">" [2] "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  54:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  55:</span> cout &lt;&lt; pFun &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  56:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  57:</span> cout &lt;&lt; <span style="color: #006080">"[5] = 0x"</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  58:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  59:</span> cout &lt;&lt; *((<span style="color: #0000ff">int</span>*)(&dd)+5) &lt;&lt; endl; <span style="color: #008000">// ???</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  60:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  61:</span> cout &lt;&lt; <span style="color: #006080">"[6] B2::ib2 = "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  62:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  63:</span> cout &lt;&lt; (<span style="color: #0000ff">int</span>)*((<span style="color: #0000ff">int</span>*)(&dd)+6) &lt;&lt;endl; <span style="color: #008000">//B2::ib2</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  64:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  65:</span> cout &lt;&lt; <span style="color: #006080">"[7] B2::cb2 = "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  66:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  67:</span> cout &lt;&lt; (<span style="color: #0000ff">char</span>)*((<span style="color: #0000ff">int</span>*)(&dd)+7) &lt;&lt; endl; <span style="color: #008000">//B2::cb2</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  68:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  69:</span> cout &lt;&lt; <span style="color: #006080">"[8] D::id = "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  70:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  71:</span> cout &lt;&lt; *((<span style="color: #0000ff">int</span>*)(&dd)+8) &lt;&lt; endl; <span style="color: #008000">//D::id</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  72:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  73:</span> cout &lt;&lt; <span style="color: #006080">"[9] D::cd = "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  74:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  75:</span> cout &lt;&lt; (<span style="color: #0000ff">char</span>)*((<span style="color: #0000ff">int</span>*)(&dd)+9) &lt;&lt; endl;<span style="color: #008000">//D::cd</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  76:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  77:</span> cout &lt;&lt; <span style="color: #006080">"[10] = 0x"</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  78:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  79:</span> cout &lt;&lt; (<span style="color: #0000ff">int</span>*)*((<span style="color: #0000ff">int</span>*)(&dd)+10) &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  80:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  81:</span> <span style="color: #008000">//---------------------</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  82:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  83:</span> cout &lt;&lt; <span style="color: #006080">"[11] D::B::_vptr-&gt;"</span> &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  84:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  85:</span> pFun = (Fun)pVtab[11][0];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  86:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  87:</span> cout &lt;&lt; <span style="color: #006080">" [0] "</span>; pFun(); <span style="color: #008000">//D::f();</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  88:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  89:</span> pFun = (Fun)pVtab[11][1];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  90:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  91:</span> cout &lt;&lt; <span style="color: #006080">" [1] "</span>; pFun(); <span style="color: #008000">//B::Bf();</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  92:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  93:</span> pFun = (Fun)pVtab[11][2];</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  94:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  95:</span> cout &lt;&lt; <span style="color: #006080">" [2] "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  96:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  97:</span> cout &lt;&lt; pFun &lt;&lt; endl;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  98:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060">  99:</span> cout &lt;&lt; <span style="color: #006080">"[12] B::ib = "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060"> 100:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060"> 101:</span> cout &lt;&lt; *((<span style="color: #0000ff">int</span>*)(&dd)+12) &lt;&lt; endl; <span style="color: #008000">//B::ib</span></pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060"> 102:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060"> 103:</span> cout &lt;&lt; <span style="color: #006080">"[13] B::cb = "</span>;</pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: #f4f4f4; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060"> 104:</span>&#160; </pre>

    <pre style="border-bottom-style: none; padding-bottom: 0px; line-height: 12pt; border-right-style: none; background-color: white; margin: 0em; padding-left: 0px; width: 100%; padding-right: 0px; font-family: consolas, &#39;Courier New&#39;, courier, monospace; border-top-style: none; color: black; font-size: 8pt; border-left-style: none; overflow: visible; padding-top: 0px"><span style="color: #606060"> 105:</span> cout &lt;&lt; (<span style="color: #0000ff">char</span>)*((<span style="color: #0000ff">int</span>*)(&dd)+13) &lt;&lt;endl;<span style="color: #008000">//B::cb</span></pre></p>
  </div>
</div>

<p>
  下面给出运行后的结果(分VC++和GCC两部份)
</p>

<p>
  <a href="/images/uploads/2010/04/image6.png" rel="lightbox[983]"><img style="border-bottom: 0px; border-left: 0px; display: inline; border-top: 0px; border-right: 0px" title="image" border="0" alt="image" src="/images/uploads/2010/04/image_thumb4.png" width="625" height="423" /></a>
</p>

<p>
  关于虚拟继承的运行结果我就不画图了(前面的作图已经让我产生了很严重的厌倦感,所以就偷个懒了,大家见谅了)
</p>

<p>
  在上面的输出结果中,我用不同的颜色做了一些标明。我们可以看到如下的几点:
</p>

<p>
  1)无论是GCC还是VC++,除了一些细节上的不同,其大体上的对象布局是一样的。也就是说,先是B1(黄色),然后是B2(绿色),接着是D(灰色),而B这个超类(青蓝色)的实例都放在最后的位置。
</p>

<p>
  2)关于虚函数表,尤其是第一个虚表,GCC和VC++有很重大的不一样。但仔细看下来,还是VC++的虚表比较清晰和有逻辑性。
</p>

<p>
  3)VC++和GCC都把B这个超类放到了最后,而VC++有一个NULL分隔符把B和B1和B2的布局分开。GCC则没有。
</p>

<p>
  4)VC++中的内存布局有两个地址我有些不是很明白,在其中我用红色标出了。取其内容是-4。接道理来说,这个指针应该是指向B类实例的内存地址(这个做法就是为了保证重复的父类只有一个实例的技术)。但取值后却不是。这点我目前还并不太清楚,还向大家请教。
</p>

<p>
  5)GCC的内存布局中在B1和B2中则没有指向B的指针。这点可以理解,编译器可以通过计算B1和B2的size而得出B的偏移量。
</p>

<p>
  <strong>结束语</strong>
</p>

<p>
  C++这门语言是一门比较复杂的语言,对于程序员来说,我们似乎永远摸不清楚这门语言背着我们在干了什么。需要熟悉这门语言,我们就必需要了解C++里面的那些东西,需要我们去了解他后面的内存对象。这样我们才能真正的了解C++,从而能够更好的使用C++这门最难的编程语言。
</p>

<p>
  在文章束之前还是介绍一下自己吧。我从事软件研发有十个年头了,目前是软件开发技术主管,技术方面,主攻Unix/C/C++,比较喜欢网络上的技术,比如分布式计算,网格计算,P2P,Ajax等一切和互联网相关的东西。管理方面比较擅长于团队建设,技术趋势分析,项目管理。欢迎大家和我交流,我的MSN和Email是:haoel@hotmail.com
</p>

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