标签：style class blog c code ext
在C++继承模型中，一个派生类对象表现出来的东西，是其自己的成员加上其基类成员的总和。但这些成员如何摆放，标准并未强制规定。一般而言，先摆放基类成员，内存向高地址增长。#include <iostream>
#include <vector>
using namespace std;
class Foo {
public:
int val;
char bit1, bit2, bit3;
};
class A {
public:
int val;
char bit1;
};
class B : public A {
public:
char bit2;
};
class C : public B {
public:
char bit3;
};
int main()
{
cout << "size Foo = " << sizeof(Foo) << endl;
cout << "size C = " << sizeof(C) << endl;
system("pause");
return 0;
}
#include <iostream>
#include <vector>
using namespace std;
class Foo {
public:
int x;
};
class Bar : public Foo {
public:
int y;
virtual void func()
{}
};
int main()
{
Bar bar;
cout << &bar << endl;
cout << &bar.x << endl;
cout << &bar.y << endl;
system("pause");
return 0;
}
#include <iostream>
#include <vector>
using namespace std;
class A {
public:
int x;
};
class B {
public:
int y;
};
class C : public A, public B {
public:
int z;
};
int main()
{
C c;
A *pa = &c;
B *pb = &c;
cout << &c << endl;
cout << pa << endl;
cout << pb << endl;
system("pause");
return 0;
}
// 伪代码 pb = (B *)(((char *)&c) + sizeof(A))
标签：style class blog c code ext
原文地址：http://blog.csdn.net/nestler/article/details/26804243
