1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 // <tuple> 10 11 // template <class... Types> class tuple; 12 13 // template <size_t I, class... Types> 14 // struct tuple_element<I, tuple<Types...> > 15 // { 16 // typedef Ti type; 17 // }; 18 19 // UNSUPPORTED: c++98, c++03 20 21 #include <tuple> 22 #include <type_traits> 23 24 #include "test_macros.h" 25 26 template <class T, std::size_t N, class U> 27 void test() 28 { 29 static_assert((std::is_same<typename std::tuple_element<N, T>::type, U>::value), ""); 30 static_assert((std::is_same<typename std::tuple_element<N, const T>::type, const U>::value), ""); 31 static_assert((std::is_same<typename std::tuple_element<N, volatile T>::type, volatile U>::value), ""); 32 static_assert((std::is_same<typename std::tuple_element<N, const volatile T>::type, const volatile U>::value), ""); 33 #if TEST_STD_VER > 11 34 static_assert((std::is_same<typename std::tuple_element_t<N, T>, U>::value), ""); 35 static_assert((std::is_same<typename std::tuple_element_t<N, const T>, const U>::value), ""); 36 static_assert((std::is_same<typename std::tuple_element_t<N, volatile T>, volatile U>::value), ""); 37 static_assert((std::is_same<typename std::tuple_element_t<N, const volatile T>, const volatile U>::value), ""); 38 #endif 39 } 40 41 int main(int, char**) 42 { 43 test<std::tuple<int>, 0, int>(); 44 test<std::tuple<char, int>, 0, char>(); 45 test<std::tuple<char, int>, 1, int>(); 46 test<std::tuple<int*, char, int>, 0, int*>(); 47 test<std::tuple<int*, char, int>, 1, char>(); 48 test<std::tuple<int*, char, int>, 2, int>(); 49 50 return 0; 51 } 52