GLFW - Window close callback?

[Henri Korpela]

Hello, I created a very primitive application which is both DirectX & OpenGL compatible. As I already mentioned, it's primitive, but it works... almost. There is a slight problem and it's about the callback, which handles the window closure in GLFW API. So, the question is: what kind of function definition will handle the callback properly? I know that the callback in GLFW is this:

int glfwSetWindowCloseCallback(void);

I'm looking for proper implementation of the callback function.

PLEASE NOTE: WinAPI is out of the question, because the goal of my OpenGL implementation of my application is to be compatible with non-Microsoft systems. This is why I have two different APIS: DirectX & OpenGL.