Splitting templated C++ classes into .hpp/.cpp files--is it possible?

Question

I am getting errors trying to compile a C++ template class which is split between a .hpp and .cpp file:

$ g++ -c -o main.o main.cpp         


        

Answer 1

You need to have everything in the hpp file. The problem is that the classes aren't actually created until the compiler sees that they're needed by some OTHER cpp file - so it has to have all the code available to compile the templated class at that time.

One thing that I tend to do is to try to split my templates into a generic non-templated part (which can be split between cpp/hpp) and the type-specific template part which inherits the non-templated class.