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 // Triggers a Clang assertion: https://bugs.llvm.org/show_bug.cgi?id=45879 10 // UNSUPPORTED: clang-13, clang-14 11 12 // <tuple> 13 14 // template <class... Types> class tuple; 15 16 // template <class... UTypes> 17 // tuple& operator=(const tuple<UTypes...>& u); 18 19 // UNSUPPORTED: c++03 20 21 #include <tuple> 22 #include <string> 23 #include <cassert> 24 25 #include "test_macros.h" 26 27 struct B { 28 int id_; 29 30 constexpr explicit B(int i = 0) : id_(i) {} 31 }; 32 33 struct D : B { 34 constexpr explicit D(int i = 0) : B(i) {} 35 }; 36 37 struct NonAssignable { 38 NonAssignable& operator=(NonAssignable const&) = delete; 39 NonAssignable& operator=(NonAssignable&&) = delete; 40 }; 41 42 struct NothrowCopyAssignable { 43 NothrowCopyAssignable& operator=(NothrowCopyAssignable const&) noexcept { return *this; } 44 }; 45 46 struct PotentiallyThrowingCopyAssignable { 47 PotentiallyThrowingCopyAssignable& operator=(PotentiallyThrowingCopyAssignable const&) { return *this; } 48 }; 49 50 TEST_CONSTEXPR_CXX20 51 bool test() 52 { 53 { 54 typedef std::tuple<long> T0; 55 typedef std::tuple<long long> T1; 56 T0 t0(2); 57 T1 t1; 58 t1 = t0; 59 assert(std::get<0>(t1) == 2); 60 } 61 { 62 typedef std::tuple<long, char> T0; 63 typedef std::tuple<long long, int> T1; 64 T0 t0(2, 'a'); 65 T1 t1; 66 t1 = t0; 67 assert(std::get<0>(t1) == 2); 68 assert(std::get<1>(t1) == int('a')); 69 } 70 { 71 typedef std::tuple<long, char, D> T0; 72 typedef std::tuple<long long, int, B> T1; 73 T0 t0(2, 'a', D(3)); 74 T1 t1; 75 t1 = t0; 76 assert(std::get<0>(t1) == 2); 77 assert(std::get<1>(t1) == int('a')); 78 assert(std::get<2>(t1).id_ == 3); 79 } 80 { 81 D d(3); 82 D d2(2); 83 typedef std::tuple<long, char, D&> T0; 84 typedef std::tuple<long long, int, B&> T1; 85 T0 t0(2, 'a', d2); 86 T1 t1(1, 'b', d); 87 t1 = t0; 88 assert(std::get<0>(t1) == 2); 89 assert(std::get<1>(t1) == int('a')); 90 assert(std::get<2>(t1).id_ == 2); 91 } 92 { 93 // Test that tuple evaluates correctly applies an lvalue reference 94 // before evaluating is_assignable (i.e. 'is_assignable<int&, int&>') 95 // instead of evaluating 'is_assignable<int&&, int&>' which is false. 96 int x = 42; 97 int y = 43; 98 std::tuple<int&&> t(std::move(x)); 99 std::tuple<int&> t2(y); 100 t = t2; 101 assert(std::get<0>(t) == 43); 102 assert(&std::get<0>(t) == &x); 103 } 104 return true; 105 } 106 107 int main(int, char**) 108 { 109 test(); 110 #if TEST_STD_VER >= 20 111 static_assert(test()); 112 #endif 113 114 { 115 using T = std::tuple<int, NonAssignable>; 116 using U = std::tuple<NonAssignable, int>; 117 static_assert(!std::is_assignable<T&, U const&>::value, ""); 118 static_assert(!std::is_assignable<U&, T const&>::value, ""); 119 } 120 { 121 typedef std::tuple<NothrowCopyAssignable, long> T0; 122 typedef std::tuple<NothrowCopyAssignable, int> T1; 123 static_assert(std::is_nothrow_assignable<T0&, T1 const&>::value, ""); 124 } 125 { 126 typedef std::tuple<PotentiallyThrowingCopyAssignable, long> T0; 127 typedef std::tuple<PotentiallyThrowingCopyAssignable, int> T1; 128 static_assert(std::is_assignable<T0&, T1 const&>::value, ""); 129 static_assert(!std::is_nothrow_assignable<T0&, T1 const&>::value, ""); 130 } 131 132 return 0; 133 } 134