为什么使用__stdcall作为函数指针

Question

I was looking at some code like the one mentioned here: Function pointers for winapi functions (stdcall/cdecl) , Function pointer and calling convention , etc.

What is the need, benefit for declaring the calling type of a function pointer as __stdcall ?

Why declare the calling type for a function pointer at all?

Answer 1

Embedding a calling convention specifier in a function pointer allows you to use that calling convention when calling functions through that pointer. __stdcall is the calling convention used to call Win32 API functions.

The benefit of specifying it in a function pointer is being able to match a different calling convention according to your code's needs (eg when loading an external library's function via late binding ). Library headers should specify them as a good programming practice.

There's a caveat though: if you embed a wrong calling convention in a function pointer, the compiler might be powerless to help you detect that and you might end up doing bad things at runtime.