As the title suggest I'm searching for an header wich includes only the necessary typedefs for GL Types and is portable (GLES2 for android and emscripten, Windows, Linux, Mac)

I need that for a simple reason:

-I have public interfaces (no GL exposed, except for the hook class in case someone want to add GL code)
-Public interfaces are implemented by private classes
-Private classes are separed into headers and source files
-Private Headers only expose gl types (GLEnum, GLInt, GLfloat) etc.. <-----!!! so why include glew.h if I need a bunch of typedefs?

=> quick recompilation, indipendence from the GL provider (GLEW, glee, glLoadGen) etc.

Why does not exist something so simple? O_O I can hack such header out of glew.h but I have the feeling that I'm including much useless system headers anyway that can be stripped by someone with more knowledge about what's going on inside glew.h. Also glew has not all types in one place, but have those types separed into sections sometimes with #defines that I have to track back (thousand lines of code sigh).