How can I resolve this link error in Visual Studio (LNK2005)?

Question

I keep having linker errors of the following form:

libcmtd.dll msvmrtd.dll some element(ex: _mkdir ) already defined...

Answer 1

Check a few things:

1. Are your header files guarded. I.e. do they have #ifndef guards.

2. Are you defining (non-template) functions in headers without the inline keyword. That messes lots of stuff up.

3. Are you trying to define templates in a .cpp file. All template definitions need to be in headers.

Post some code and exact error text please!