MSVC中的模板模板参数错误，但不包括Clang。 为什么？

Question

I have written this code to help me sort indices that refer to a collection, according to some predicate:

#include <algorithm>
#include <functional>
#include <vector>

template<template<class> class Pred = std::less>
struct element_is_pred
{
    template<class C>
    struct type : private Pred<typename C::value_type>
    {
        typedef Pred<typename C::value_type> Base;
        C const *c;
        type(C const &c, Base const &pred = Base())
            : Base(pred), c(&c) { }
        bool operator()(
            typename C::size_type const i,
            typename C::size_type const j) const
        { return this->Base::operator()((*c)[i], (*c)[j]); }
    };
};

template<template<class> class P, class C>
static element_is_pred<P>::template type<C const> element_is(
    C const &c,
    P<typename C::value_type> const &pred = P<typename C::value_type>())
{
    return typename element_is_pred<P>::template type<C const>(c, pred);
}

and I'm using it like this:

int main()
{
    std::vector<size_t> temp;
    std::vector<size_t> indices;
    indices.push_back(0);
    std::stable_sort(
        indices.begin(),
        indices.end(),
        element_is<std::less>(temp));
}

and when I compile it with Clang 3.2:

clang++ -fsyntax-only Test.cpp

it compiles fine.

But when I try to compile it with Visual C++ 2013, I get tons of errors, like:

test.cpp(23) : warning C4346: 'element_is_pred<Pred>::type<const C>' : dependent name is not a type
        prefix with 'typename' to indicate a type
test.cpp(23) : error C2146: syntax error : missing ';' before identifier 'element_is'
test.cpp(23) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int

Which compiler is correct?
What is the correct way to write the code to do this?

Answer 1

GCC gives the following error:

error: need 'typename' before 'element_is_pred<Pred>::type<const C>' because 'element_is_pred<Pred>' is a dependent scope

Following that advice, I can get the program to build on GCC by prepending typename :

static typename element_is_pred<P>::template type<C const> element_is(
       ^^^^^^^^

Clang allows the modified version as well.