layer0/GraphicsUtil.h (6 lines of code) (raw):
#pragma once
#include "os_gl.h"
// Generic Error Handing
bool glCheckOkay();
void GLAPIENTRY gl_debug_proc(GLenum, GLenum, GLuint, GLenum, GLsizei, const GLchar *, const void *);
// userParam is qualified as const in OpenGL 4.4 spec but non-const in OpenGL 4.3 spec
void GLAPIENTRY gl_debug_proc(GLenum, GLenum, GLuint, GLenum, GLsizei, const GLchar *, void *);
size_t gl_sizeof(GLenum type);