*.h or *.hpp for your class definitions?

Question

I've always used a `*.h` file for my class definitions, but after reading some boost library code, I realised they all use `*.hpp`. I've always had an aversion to that file extension, I think mainly because I'm not used to it. What are the advantages and disadvantages of using `*.hpp` over `*.h`?

Answer 1

*.hpp cues the reader that it is used by a *.cpp source code file, which aids in identifying the dependencies..

likewise, as you know, *.h files are used by *.c files...

However, I have seen *.c files being included

all the #include does is tell the compiler to insert the exact contents of the file.