Question

Sometimes I am working with relatively complex (and sometimes confusing – with the way they are laid out by whoever wrote it originally) abstract classes. When inheriting from it, I sometimes encounter cannot instantiate abstract class and most of the time it is because I forgot to declare & implement a pure virtual function. Can I get more information from the compiler about which function it found I did not implement instead of hunting for it?

Answer 1

Are you using Visual Studio? If so, then switch from Error List tab to Output tab. There will be something like:

main.cpp(8): error C2259: 'foo' : cannot instantiate abstract class
          due to following members:
          'void Foo::method(char)' : is abstract