Internal typedefs in C++ - good style or bad style?

Question

Something I have found myself doing often lately is declaring typedefs relevant to a particular class inside that class, i.e.

class Lorem
{
    typedef boost         


        

Answer 1

Typdefs are definitely are good style. And all your "reasons I like" are good and correct.

About problems you have with that. Well, forward declaration is not a holy grail. You can simply design your code to avoid multi level dependencies.

You can move typedef outside the class but Class::ptr is so much prettier then ClassPtr that I don't do this. It is like with namespaces as for me - things stay connected within the scope.

Sometimes I did

Trait::ptr
Trait::collection
Trait::map

And it can be default for all domain classes and with some specialization for certain ones.