Question

I’m writing a template class, let’s say

template <class T>
class bla {
    bla() ;
    ~bla() ;
};

template <class T>
bla<t>::bla(){}

template <class T>
b<t>::~b(){}

This works fine as long as T is int, char, and so on … but in case that it will be a custom class MyClass, it will requiere the headerfile MyClass.h to be included, or am I wrong?

Question: How can this be done in a template-ish way, i.e. something like

#include "T.h"

Cheers!

Answer 1

When you use bla<MyClass> you need to have included the definition of bla and the definition of MyClass. It isn’t necessary that MyClass is known when bla is defined. The magic about this is called “two-phase name look-up”: while compiling the template definition all names not depending on the template parameter are looked up. During the second phase, when the template is instantiated, all remaining names are looked up in the context of the instantiation.