Hi Bernhard,
The problem is you have forgotten to include the template functions in your testmain.cpp (or alternatively, in your testt.h).
#include "testt.h" #include "testt.cpp" #include <iostream>
main() { TestT<double> w; w.setvalue( 2.0 ); cout << w.getvalue( ); }
It's rather unconventional to put the template methods in a .cpp file. Usually they are put in the header file.
I have seen one convention that put template methods, template functions and inline functions in a .inl file, at one company I worked at.
HTH, --Eljay