(C++) Stuck between a rock and a very, very hard place.

Does the filetype_extensions.conf file have a C++ line? Try adding *.h to that (in addition to commenting out the C line).

If that doesn't work, try changing the file names to .hpp.
Hopefully your instructor won't mind, since you're still putting the class header in a separate file from its implementation, as required.

I don't know geany at all, but some other editors get it right if you insert the following line as the first line in every .h file:

Code:

// Hey, geany, this is a C++ file

(The exact text doesn't matter, what matters is that it's a C++ comment. C only allows /* */ style comments)

Good luck.