Functor errors

[Dae]

Would appreciate a pointer here (pun intended).

It's been a long time since I've touched anything low-level. Apologies if this is simple. I didn't post this in GD because it's basic C, not game related. I'm receiving errors with an app that uses SDL. I've found the error seems to vary based on platform. I'm not sure, it looks like a simple declaration issue, causing error on assignment.

error: cannot convert ‘void (*)(GLuint)’ to ‘void ()(GLuint)’ in assignment

Code:

middle of SDL_opengl.h

GLAPI void APIENTRY glUseProgram (GLuint);

top of renderer_ogl.cpp

typedef void (APIENTRY* PFNGLUSEPROGRAMPROC) (GLuint program);
PFNGLUSEPROGRAMPROC glUseProgram = 0;

middle of renderer_ogl.cpp

glUseProgram = (PFNGLUSEPROGRAMPROC) SDL_GL_GetProcAddress("glUseProgram");

I changed the last one to dereference:

glUseProgram = *(PFNGLUSEPROGRAMPROC) SDL_GL_GetProcAddress("glUseProgram");

It said

error: cannot convert ‘void ()(GLuint)’ to ‘void ()(GLuint)’ in assignment

I actually recall function pointers were suppose to be pointers... the error doesn't really make sense, and I'm just confusing myself. Until tomorrow.

Thanks

[grumpy]

The asterix you added is being applied to the return value from the function, not to the function pointer.

[Dae]

You're right. I don't think that original code is incorrect now. I think I need to use a compiler flag. It's a little disorienting, using command-line compiler + some Python called waf-script. It's probably just some compiler/SDL issue.

Sorry for the topic, thanks anyway.