对象内存布局 (15)
来源:互联网 发布:看到祖国如此流氓 知乎 编辑:程序博客网 时间:2024/05/14 21:07
前篇:http://blog.csdn.net/pathuang68/archive/2009/04/24/4105851.aspx
和对象内存布局 (14)差不多,只是改动了两个继承关系。几个类的继承关系如下图,这种继承方式不是很有实际意义,在此纯粹是探究类的memory layout。
代码如下:
#include <iostream>
using namespace std;
class Base
{
public:
int base_member;
};
class Derived1 : public virtual Base
{
public:
int derived1_member;
};
class Derived2 : public virtual Base
{
public:
int derived2_member;
};
class ChildDerived : public virtual Derived1, public virtual Derived2
{
public:
int childderived_member;
};
int main(void)
{
ChildDerived cd;
cout << "sizeof(Base) = /t/t" << sizeof(Base) << endl;
cout << "sizeof(Derived1) = /t" << sizeof(Derived1) << endl;
cout << "sizeof(Derived2) = /t" << sizeof(Derived2) << endl;
cout << "sizeof(ChildDerived) = /t" << sizeof(ChildDerived) << endl;
cout << endl;
cout << "ChildDerived object's vbptr = " << (int*)&cd << endl;
cout << endl;
cout << "Address of virtual base class table of ChildDerived object = " << (int*)(*((int*)&cd)) << endl;
cout << "Item 1 in ChildDerived's virtual base class table = " << *((int*)*(int*)(&cd) + 0) << endl;
cout << "Item 2 in ChildDerived's virtual base class table = " << *((int*)*(int*)(&cd) + 1) << endl;
cout << "Item 3 in ChildDerived's virtual base class table = " << *((int*)*(int*)(&cd) + 2) << endl;
cout << "Item 4 in ChildDerived's virtual base class table = " << *((int*)*(int*)(&cd) + 3) << endl;
cout << "Item 4 in ChildDerived's virtual base class table = " << *((int*)*(int*)(&cd) + 4) << endl;
cout << endl;
cout << "Address of virtual base class table of Derived1 object = " << (int*)*((int*)&cd + 3) << endl;
cout << "Item 1 in Derived1's virtual base class table = " << *((int*)*((int*)&cd + 3) + 0) << endl;
cout << "Item 2 in Derived1's virtual base class table = " << *((int*)*((int*)&cd + 3) + 1) << endl;
cout << "Item 3 in Derived1's virtual base class table = " << *((int*)*((int*)&cd + 3) + 2) << endl;
cout << endl;
cout << "Address of virtual base class table of Derived2 object = " << (int*)*((int*)&cd + 5) << endl;
cout << "Item 1 in Derived2's virtual base class table = " << *((int*)*((int*)&cd + 5) + 0) << endl;
cout << "Item 2 in Derived2's virtual base class table = " << *((int*)*((int*)&cd + 5) + 1) << endl;
cout << "Item 3 in Derived2's virtual base class table = " << *((int*)*((int*)&cd + 5) + 2) << endl;
cout << endl;
cout << "The address of base class Derived1's instance = " << (Derived1*)&cd << endl;
cout << "The address of base class Derived2's instance = " << (Derived2*)&cd << endl;
cout << "The address of base class Base's instance = /t" << (Base*)&cd << endl;
return 0;
}
注意:因为可能出现负数,所以在上面的程序中,将原来的unsigned long* 改为了int*。运行结果:
图解如下:
后篇:http://blog.csdn.net/pathuang68/archive/2009/04/24/4105922.aspx
- 对象内存布局 (15)
- 对象内存布局 (15)
- C++内存对象布局
- c++对象,内存布局
- c++对象内存布局
- 对象内存布局 (1)
- 对象内存布局 (2)
- 对象内存布局 (3)
- 对象内存布局 (4)
- 对象内存布局 (5)
- 对象内存布局 (6)
- 对象内存布局 (7)
- 对象内存布局 (8)
- 对象内存布局 (9)
- 对象内存布局 (10)
- 对象内存布局 (11)
- 对象内存布局 (12)
- 对象内存布局 (13)
- 为什么会出现LNK2005"符号已定义"的链接错误?
- sql 优化查询
- Ext.data.Store
- SQL2000数据库导入.ldf和.mdf数据库文件方法
- 饮食补铁 能治贫血
- 对象内存布局 (15)
- 简单的运营法则
- 学习COM组件编程
- 将某个目录上的Excel表,导入到数据库中
- Some great libs
- .NET2008(C#)使用Ajax技术实例
- Make your pages load faster by combining and compressing javascript and css files
- 对象内存布局 (16)
- sql server中guest用戶