I just downloaded the OpenGL ES 1.1 glext.h file from Khronos and noticed this on line 1036:
GL_API void GL_APIENTRY *glMapBufferRangeEXT (GLenum target, GLintptr offset, GLsizeiptr length, GLbitfield access);
Compiling on Windows (Visual Studio) this will roughly resolve to (ignoring declspec):
void __stdcall *glMapBufferRangeEXT
Which of course will not compile with a C2165 error. An easy repro is to just put in this prototype:
void __stdcall *Foo();
The GL function is returning a void pointer, and glMapBufferOES has a correct prototype for this on line 789.
Am I completely wrong, or not understanding something?