Instead of writing a function as follows:

template<typename T>
typename T::allocator_type::rebind<typename T::key_type> Func(T &container)
{
    typename T::allocator_type::rebind<typename T::key_type> obj;
    return obj;
}

It would be nice, inside the body of the function, to have a simple
keyword for the function's return type, like this:

template<typename T>
typename T::allocator_type::rebind<typename T::key_type> Func(T &container)
{
    return_t obj;
    return obj;
}

Furthermore this new keyword could be used in functions with 'auto' return type:

auto Func2(double a, int b)
{
    return_t obj;

    return a + b;
}

This could get pretty elaborate where one template function calls
another, for example:

template<class A, class B>
auto Func4(A a, B b)
{
    return_t obj;

    return Converter<B,A>::Process(a) + Converter<B,A>::Process(b) +
SumOf<A,B>(a,b);
}