Some say, we are using “.cc” as extension for C++ files to differentiate from C files (which has an extension “.c”), likewise we are using using “.hh” as extension for C++ header files to differentiate from C header files (which has an extension “.h”).
That is exactly the reason. It is just to differentiate CPP headers from C headers.
Some programmers and libraries, such as Boost, use .hpp for CPP headers. My personal choice is this:
- example.c
- example.cpp
- example.h
- example.h++
Even if they all belong to a huge project, you can still figure out which one is which. No description is needed.