Im using allegro, and im trying to add a header file to my code, but i get errors such as: [Linker Error] undefined reference to System::System() or [Linker Error] undefined reference to System::~System()
This won't help much but word of advice: Don't use Dev-C++, it hasn't been updated in five years or so. It lacks some great features that other IDEs today have, such as Code::Blocks and Microsoft Visual Studio.
Where's System.cpp with the definitions of System() and ~System()? Also move Setup() to it, header files aren't supposed to keep non inlined function definitions.