求助：关于C++自增自减问题
以下程序结果为什么是这样？？
{
int a=10;
cout<<a+ ++a<<endl;//输出22
a=10;
cout<<++a+ ++a<<endl;//输出24
}
cout<<a+ ++a<<endl;//输出22
001017CF mov eax,dword ptr [a]
001017D2 add eax,1
001017D5 mov dword ptr [a],eax
001017D8 mov esi,esp
001017DA mov ecx,dword ptr [__imp_std::endl (1082A8h)]
001017E0 push ecx
001017E1 mov edx,dword ptr [a]
001017E4 add edx,dword ptr [a]
001017E7 mov edi,esp
001017E9 push edx
001017EA mov ecx,dword ptr [__imp_std::cout (1082A4h)]
001017F0 call dword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (1082A0h)]
001017F6 cmp edi,esp
001017F8 call @ILT+320(__RTC_CheckEsp) (101145h)
001017FD mov ecx,eax
001017FF call dword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (10829Ch)]
00101805 cmp esi,esp
00101807 call @ILT+320(__RTC_CheckEsp) (101145h)
a=10;
0010180C mov dword ptr [a],0Ah
cout<<++a+ ++a<<endl;//输出24
00101813 mov eax,dword ptr [a]
00101816 add eax,1
00101819 mov dword ptr [a],eax
0010181C mov ecx,dword ptr [a]
0010181F add ecx,1
00101822 mov dword ptr [a],ecx
00101825 mov esi,esp
00101827 mov edx,dword ptr [__imp_std::endl (1082A8h)]
0010182D push edx
0010182E mov eax,dword ptr [a]
00101831 add eax,dword ptr [a]
00101834 mov edi,esp
00101836 push eax
00101837 mov ecx,dword ptr [__imp_std::cout (1082A4h)]
0010183D call dword ptr [__imp_std::basic_ostream<char,std::char_traits<char> >::operator<< (1082A0h)]
用反汇编来说话
cout<<a+ ++a<<endl;// ==》a++; cout<<a+a;所以22
cout<<++a+ ++a<<endl // ==>a++;a++;cout<< a+a
