1//===----------------------------------------------------------------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is dual licensed under the MIT and the University of Illinois Open 6// Source Licenses. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9 10// <tuple> 11 12// template <class... Types> class tuple; 13 14// template <class... Types> 15// class tuple_size<tuple<Types...>> 16// : public integral_constant<size_t, sizeof...(Types)> { }; 17// 18// LWG #2212 says that tuple_size and tuple_element must be 19// available after including <utility> 20 21#include <cstddef> 22#include <utility> 23#include <type_traits> 24 25template <class T, std::size_t N, class U, size_t idx> 26void test() 27{ 28 static_assert((std::is_base_of<std::integral_constant<std::size_t, N>, 29 std::tuple_size<T> >::value), ""); 30 static_assert((std::is_base_of<std::integral_constant<std::size_t, N>, 31 std::tuple_size<const T> >::value), ""); 32 static_assert((std::is_base_of<std::integral_constant<std::size_t, N>, 33 std::tuple_size<volatile T> >::value), ""); 34 static_assert((std::is_base_of<std::integral_constant<std::size_t, N>, 35 std::tuple_size<const volatile T> >::value), ""); 36 static_assert((std::is_same<typename std::tuple_element<idx, T>::type, U>::value), ""); 37 static_assert((std::is_same<typename std::tuple_element<idx, const T>::type, const U>::value), ""); 38 static_assert((std::is_same<typename std::tuple_element<idx, volatile T>::type, volatile U>::value), ""); 39 static_assert((std::is_same<typename std::tuple_element<idx, const volatile T>::type, const volatile U>::value), ""); 40} 41 42int main() 43{ 44 test<std::pair<int, int>, 2, int, 0>(); 45 test<std::pair<int, int>, 2, int, 1>(); 46 test<std::pair<const int, int>, 2, int, 1>(); 47 test<std::pair<int, volatile int>, 2, volatile int, 1>(); 48 test<std::pair<char *, int>, 2, char *, 0>(); 49 test<std::pair<char *, int>, 2, int, 1>(); 50} 51