| template<int I, int... Is> |
| struct Interface; |
| |
| template<int I> |
| struct Interface<I> |
| { |
| static int accumulate() |
| { |
| return I; |
| } |
| }; |
| |
| template<int I, int... Is> |
| struct Interface |
| { |
| static int accumulate() |
| { |
| return I + Interface<Is...>::accumulate(); |
| } |
| }; |
| |
| // Note: split this into a separate test if a |
| // cxx_variadic_template_template_parameters feature is added. |
| |
| template<typename T> |
| struct eval { |
| enum { |
| Matched = 0 |
| }; |
| }; |
| |
| template<template<typename...> class T, typename... U> |
| struct eval<T<U...> > { |
| enum { |
| Matched = 1 |
| }; |
| }; |
| |
| template<typename...> |
| struct A { |
| |
| }; |
| template<typename T> |
| struct B { |
| |
| }; |
| template<typename T, typename U> |
| struct C { |
| |
| }; |
| template<typename T, typename U, typename...> |
| struct D { |
| |
| }; |
| |
| // Note: This test assumes that a compiler supporting this feature |
| // supports static_assert. Add a workaround if that does not hold. |
| static_assert(eval<A<> >::Matched, "A Matches"); |
| static_assert(eval<A<int> >::Matched, "A Matches"); |
| static_assert(eval<A<int, char> >::Matched, "A Matches"); |
| static_assert(eval<B<int> >::Matched, "B Matches"); |
| static_assert(eval<C<int, char> >::Matched, "C Matches"); |
| static_assert(eval<D<int, char> >::Matched, "D Matches"); |
| static_assert(eval<D<int, char, bool> >::Matched, "D Matches"); |
| static_assert(eval<D<int, char, bool, double> >::Matched, "D Matches"); |