Thread: Questions on typedef

I notice you more experienced programmers use typedef a lot. I have some questions:

1. When should you use typedef? When writing:

Code:

std::list<myType>::iterator

100 times can be easier expressed as:

Code:

typedef std::list<myType>::iterator list_itr;
list_itr it = a_list.begin();

2. I notice often typedefs are written at global scope. Do typedefs follow normal scoping rules? Should they typically be written at global scope?

EDIT:

i guess that's actually:

Code:

std::list<myType>::std::iterator