Question

When compiling :

#include <vector>

template<class T> class foo {

    void bar() {
        std::vector<T> x;
        std::vector<T>::iterator i = x.begin();

    }
};


int main() {
    return 0;
}

I get :

# g++ ~test.cpp
test.cpp: In member function `void foo<T>::bar()':
test.cpp:7: error: expected `;' before "i"

Shouldn’t this work?

g++ version 3.4.3 on RHEL.

Answer 1

You can, but you need to tell it that iterator there is a type (it doesn’t know, because in general it can depend on T – as vector is a template type, and could in theory have specializations for some T where iterator is a function or something else). So, you have to use typename to indicate that it is always a type:

typename std::vector<T>::iterator i = x.begin();