Function Template: typename declaration

On GCC, The following gives me an error: no type named 'x' in 'struct Type'

On VC++, It complains about p being undeclared

struct Type
{
   static int const x = 0;
};

template <class T> void Func()
{
   typename T::x * p; // p to be pointer
}

int main()
{
   Func<Type>();
}

T::x becomes Type::x, which is an int, not a type.

You've told the compiler that T::x names a type by using typename. When Func<Type> is instantiated, T::x is not a type, so the compiler reports an error.

Since Type::x is not a type, rather a value, so when you write typename, you're telling the compiler to find a nested type with name x inside Type, but it couldn't. Hence the GCC says no type named 'x' in 'struct Type' which is more helpful than the message generated by VC++.

In C++11, the using keyword can be used for type alias

struct Type
{
    using x = static int const;
};