用汇编的眼光看C++（之拷贝、赋值函数）
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拷贝构造函数和复制函数是类里面比较重要的两个函数。两者有什么区别呢？其实也很简单，我们可以举个例子，加入有这样一个类的定义：
copy to clipboardprint?class apple
{
public:
apple() { printf("apple()!\n");}
apple(apple& a) { printf("copy apple()!\n");}
apple& operator=(apple& a) { printf("= apple()\n"); return *this;}
~apple() { printf("~apple()!\n");}
void print() const { return;}
};
class apple
{
public:
apple() { printf("apple()!\n");}
apple(apple& a) { printf("copy apple()!\n");}
apple& operator=(apple& a) { printf("= apple()\n"); return *this;}
~apple() { printf("~apple()!\n");}
void print() const { return;}
};
那么我们在如下的函数里面进行调用的时候，调用的函数分别是哪些呢？
copy to clipboardprint?void process()
{
apple a, c;
apple b =a;
c = b;
}
void process()
{
apple a, c;
apple b =a;
c = b;
} 其实汇编的结果是这样的，大家可以一起看一下，自己尝试读一下。如果一次不是很明白，可以多读几次。
copy to clipboardprint?70: apple a, c;
0040127D lea ecx,[ebp-10h]
00401280 call @ILT+70(apple::apple) (0040104b)
00401285 mov dword ptr [ebp-4],0
0040128C lea ecx,[ebp-14h]
0040128F call @ILT+70(apple::apple) (0040104b)
00401294 mov byte ptr [ebp-4],1
71: apple b =a;
00401298 lea eax,[ebp-10h]
0040129B push eax
0040129C lea ecx,[ebp-18h]
0040129F call @ILT+50(apple::apple) (00401037)
004012A4 mov byte ptr [ebp-4],2
72: c = b;
004012A8 lea ecx,[ebp-18h]
004012AB push ecx
004012AC lea ecx,[ebp-14h]
004012AF call @ILT+75(apple::operator=) (00401050)
73: }
004012B4 mov byte ptr [ebp-4],1
004012B8 lea ecx,[ebp-18h]
004012BB call @ILT+0(apple::~apple) (00401005)
004012C0 mov byte ptr [ebp-4],0
004012C4 lea ecx,[ebp-14h]
004012C7 call @ILT+0(apple::~apple) (00401005)
004012CC mov dword ptr [ebp-4],0FFFFFFFFh
004012D3 lea ecx,[ebp-10h]
004012D6 call @ILT+0(apple::~apple) (00401005)
004012DB mov ecx,dword ptr [ebp-0Ch]
004012DE mov dword ptr fs:[0],ecx
004012E5 pop edi
004012E6 pop esi
004012E7 pop ebx
004012E8 add esp,58h
004012EB cmp ebp,esp
004012ED call __chkesp (004087c0)
004012F2 mov esp,ebp
004012F4 pop ebp
004012F5 ret
70: apple a, c;
0040127D lea ecx,[ebp-10h]
00401280 call @ILT+70(apple::apple) (0040104b)
00401285 mov dword ptr [ebp-4],0
0040128C lea ecx,[ebp-14h]
0040128F call @ILT+70(apple::apple) (0040104b)
00401294 mov byte ptr [ebp-4],1
71: apple b =a;
00401298 lea eax,[ebp-10h]
0040129B push eax
0040129C lea ecx,[ebp-18h]
0040129F call @ILT+50(apple::apple) (00401037)
004012A4 mov byte ptr [ebp-4],2
72: c = b;
004012A8 lea ecx,[ebp-18h]
004012AB push ecx
004012AC lea ecx,[ebp-14h]
004012AF call @ILT+75(apple::operator=) (00401050)
73: }
004012B4 mov byte ptr [ebp-4],1
004012B8 lea ecx,[ebp-18h]
004012BB call
补充：软件开发 , C++ ,
