C++ templates declare in .h, define in .hpp

Question

I saw some code in which the developer defined a class template in a .h file, and defined its methods in a .hpp file. This caught me a bit by surprise.

Are there are

Answer 1

I've never heard of putting class declarations in .h and template definitions in .hpp. Every project I've seen has taken the approach that .h and .hpp mean the same thing and you should standardize on one (usually .h).

Template methods can be put at the end of the .h file, or they can be put in separate -inl.h files (as suggested by the Google C++ Style Guide, for example).