When should I use the keyword “typename” when using templates

Question

I\'ve been working lately on a small project, and I couldn\'t figure out something..

I\'ve been given a .h file that was containing a class, using a typename templat

Answer 1

typename and class are equivalent in template type parameter list:

template  class C;

is the same as

template  class C;

Where the typename is required is when referring to dependent names:

template  struct A {
    typedef typename T::some_type container;
};