c++11 using关键字代替typedef定义函数指针

#include <windows.h>

typedef int(__stdcall *pMessageBoxA)(HWND hWnd, LPCSTR lpText, LPCSTR lpCaption, UINT uType);
using pFnMessageBoxA = int(__stdcall *)(HWND hWnd, LPCSTR lpText, LPCSTR lpCaption, UINT uType);

int main()
{
    pMessageBoxA MessageBoxA1 = (pMessageBoxA)GetProcAddress(LoadLibraryA("User32.dll"), "MessageBoxA");
    pFnMessageBoxA MessageBoxA2 = (pFnMessageBoxA)GetProcAddress(LoadLibraryA("User32.dll"), "MessageBoxA");

    MessageBoxA1(NULL, "test1", "test", 0);
    MessageBoxA2(NULL, "test2", "test", 0);
    return 0;
}