Question

Possible Duplicate:
C++: malloc : error: invalid conversion from ‘void*’ to ‘uint8_t*’

Hello,

I have this little function

Uint32 moveSprite(Uint32 interval, void *param)
{
    SDL_Rect* spritePos = param; 
    spritePos->x++;

    return interval;
}

The problem here is quite simple, I’m using codeblocks, when i save this file as a C file, it compiles with no problems, but once I save it as a C++ file, I have this error:

error: invalid conversion from 'void*' to 'SDL_Rect*'|

Does anyone have a clue on what’s the problem here?

Answer 1

Your code is valid C, not valid C++. You need to add an explicit casting for it to compile

Either C-style:

SDL_Rect* spritePos = (SDL_Rect *)param; 

Or more C++-ish:

SDL_Rect* spritePos = static_cast<SDL_Rect *>(param); 

A better solution would be to change the parameter type instead if that’s possible for you. Avoid void * whenever you can!