Expected constructor, destructor, or type conversion before '=' token

Question

I have some extern'd variables in a namespace in a header file, and I'm trying to initialize them in its corresponding cpp file. However, I keep getting the error given in the topic title. I'm not sure what the problem is.

EX:

// Some header
namespace foo
{
    extern SDL_Surface* bar;
}

// In the impl file
#include "someheader.h"
foo::bar = 0;
.....

Any assistance is appreciated. Thanks.

Answer 1

At the file level, you can only define types (you've only written an assignment expression). So you need to change that to:

SDL_Surface* foo::bar = 0;

Answer 2

It doesn't know what type SDL_Surface is. You need to define it or at least forward declare it.