Linking files in g++

Question

Recently I have tried to compile a program in g++ (on Ubuntu). Usually i use Dev-C++ (on Windows) and it works fine there as long as I make a project and put all the necessa

Answer 1

I assume that you have declared a member function (usually in a .h or .hpp file) but have ommited the respective definition of the member function (usually in a .cpp file).

In c++, it is possible to declare a class like so:

class foo {
  void x();
  void y();
}

with a cpp file that goes like so

void foo::x() {
   do_something()
}

Note, there is no foo::y().

This poses no problem to the compiling/linking process as long as the member function foo::y() is referenced nowhere throughout the compiled code.