每个c++类都有构造函数吗？

经常看一些c++的书有这一句每个c++类都有构造函数，只是很多没写，是被编译器隐藏啦！

 

我表示对这句话的怀疑，于是有了下面的例子

 

#include <iostream>
#include <windows.h>
 
using namespace  std;
 
 
 
class CInit
{
int m_nNumber;
 
public:
void SetNumber(int nNumber)
{
m_nNumber = nNumber;
}
 
int GetNumber()
{
return m_nNumber;
}
 
};
 
 
 int main()
 {
 CInit Init;
 Init.SetNumber(5);
 cout<<Init.GetNumber()<<endl;
 return 0;
 }

 

 

看一下对应的汇编代码，很显然没有 CInit::CInit 出现

  

{
00401570   push        ebp
00401571   mov         ebp,esp
00401573   sub         esp,44h
00401576   push        ebx
00401577   push        esi
00401578   push        edi
00401579   lea         edi,[ebp-44h]
0040157C   mov         ecx,11h
00401581   mov         eax,0CCCCCCCCh
00401586   rep stos    dword ptr [edi]
28:        CInit Init;
29:        Init.SetNumber(5);
00401588   push        5
0040158A   lea         ecx,[ebp-4]
0040158D   call        @ILT+665(CInit::SetNumber) (0040129e)
30:        cout<<Init.GetNumber()<<endl;
00401592   push        offset @ILT+195(std::endl) (004010c8)
00401597   lea         ecx,[ebp-4]
0040159A   call        @ILT+255(CInit::GetNumber) (00401104)
0040159F   push        eax
004015A0   mov         ecx,offset std::cout (0047be90)
004015A5   call        @ILT+250(std::basic_ostream<char,std::char_traits<char> >::operator<<) (004010ff)
004015AA   mov         ecx,eax
004015AC   call        @ILT+480(std::basic_ostream<char,std::char_traits<char> >::operator<<) (004011e5)
31:        return 0;