Expected specifier-qualifier-list error in OpenGL ES iPhone project.

Well. Team was trying to create this first OpenGL ES code following the instructions of Chapter 1 in iPhone 3D Programming by Philip Rideout, and faced problem of specifier-qualifier-list in my .hpp file.
Well, to fix this problem do following:

1. Changed all .m in my project to .mm

Hope it helps someone facing the same problem.