以下使用 mingw 4.7.2 和 -m64 标志编译并运行得很好。
但使用 -m32 或任何 mingw 32 位版本无法编译。是错误还是我缺少编译器标志?
#include <iostream>
#include <functional>
using namespace std;
int __cdecl ccall(int i)
{
cout << i << endl;
return 0;
}
int __stdcall stdcall(int i)
{
cout << i << endl;
return 0;
}
int __fastcall fastcall(int i)
{
cout << i << endl;
return 0;
}
int main() {
std::function<int(int)> fnc = ccall;
fnc(10);
std::function<int(int)> fnstd = stdcall;
fnstd(100);
std::function<int(int)> fnfast = fastcall;
fnfast(200);
return 0;
}
错误信息:
...\Local\Temp\cc4ekW9J.s: Assembler messages:
...\Local\Temp\cc4ekW9J.s:30: Error: symbol `__ZNSt17_Function_handlerIFiiEPFiiEE9_M_invokeERKSt9_Any_datai' is already defined
...\Local\Temp\cc4ekW9J.s:80: Error: symbol `__ZNSt14_Function_base13_Base_managerIPFiiEE10_M_managerERSt9_Any_dataRKS4_St18_Manager_operation' is already defined
...\Local\Temp\cc4ekW9J.s:114: Error: symbol `__ZNSt14_Function_base13_Base_managerIPFiiEE10_M_managerERSt9_Any_dataRKS4_St18_Manager_operation' is already defined
在将调用“隐藏”在 lambda 函数中之后,我最终这样做了,它工作得很好:
template<class Ret, class... Args> class StdCall
{
public:
typedef Ret(__stdcall Fn_t)(Args...);
typedef std::function<Ret (Args...)> Functor_t;
Functor_t get(Fn_t pFn)
{
return [pFn](Args... as){
return pFn(as...);
};
}
};
auto fn1 = CdeclCall<int,int>().get( ccall );
auto fn2 = StdCall<int,int>().get( stdcall );
fn1(123);
fn2(156);