Re: typename keyword

I have a basic question about the keyword 'typename'. typename has to
be used whenever a name that depends on a template parameter is a
type. But in the function foo() below I am using
vector<int>::const_iterator without typename. How does this work? How
does the compiler know that const_iterator is not a static member?
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using std::vector;

template <typename T>
void foo(T const& cont, vector<int> vec)
{
    typename T::const_iterator tIter = cont.begin(); //This is OK

    vector<int>::const_iterator vecIter = vec.begin(); //How does this
work without typename
    typename vector<int>::const_iterator vecTypIter = vec.begin(); //do I
really need typename in this case.
}