205 lines · cpp
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-exception6//7//===----------------------------------------------------------------------===//8 9// <tuple>10 11// template <class... Types> class tuple;12 13// template <class U1, class U2>14// tuple& operator=(pair<U1, U2>&& u);15 16// UNSUPPORTED: c++0317 18#include <tuple>19#include <utility>20#include <memory>21#include <cassert>22 23#include "test_macros.h"24 25struct B26{27 int id_;28 29 explicit B(int i = 0) : id_(i) {}30 31 virtual ~B() {}32};33 34struct D35 : B36{37 explicit D(int i) : B(i) {}38};39 40struct TrackMove41{42 TrackMove() : value(0), moved_from(false) { }43 explicit TrackMove(int v) : value(v), moved_from(false) { }44 TrackMove(TrackMove const& other) : value(other.value), moved_from(false) { }45 TrackMove(TrackMove&& other) : value(other.value), moved_from(false) {46 other.moved_from = true;47 }48 TrackMove& operator=(TrackMove const& other) {49 value = other.value;50 moved_from = false;51 return *this;52 }53 TrackMove& operator=(TrackMove&& other) {54 value = other.value;55 moved_from = false;56 other.moved_from = true;57 return *this;58 }59 60 int value;61 bool moved_from;62};63 64struct NonAssignable65{66 NonAssignable& operator=(NonAssignable const&) = delete;67 NonAssignable& operator=(NonAssignable&&) = delete;68};69 70struct MoveAssignable71{72 MoveAssignable& operator=(MoveAssignable const&) = delete;73 MoveAssignable& operator=(MoveAssignable&&) = default;74};75 76struct CopyAssignable77{78 CopyAssignable& operator=(CopyAssignable const&) = default;79 CopyAssignable& operator=(CopyAssignable&&) = delete;80};81 82struct NothrowMoveAssignable83{84 NothrowMoveAssignable& operator=(NothrowMoveAssignable&&) noexcept { return *this; }85};86 87struct PotentiallyThrowingMoveAssignable88{89 PotentiallyThrowingMoveAssignable& operator=(PotentiallyThrowingMoveAssignable&&) { return *this; }90};91 92int main(int, char**)93{94 {95 typedef std::pair<long, std::unique_ptr<D>> T0;96 typedef std::tuple<long long, std::unique_ptr<B>> T1;97 T0 t0(2, std::unique_ptr<D>(new D(3)));98 T1 t1;99 t1 = std::move(t0);100 assert(std::get<0>(t1) == 2);101 assert(std::get<1>(t1)->id_ == 3);102 }103 {104 using T = std::tuple<int, NonAssignable>;105 using P = std::pair<int, NonAssignable>;106 static_assert(!std::is_assignable<T&, P&&>::value, "");107 }108 {109 using T = std::tuple<int, int, int>;110 using P = std::pair<int, int>;111 static_assert(!std::is_assignable<T&, P&&>::value, "");112 }113 {114 typedef std::tuple<NothrowMoveAssignable, long> Tuple;115 typedef std::pair<NothrowMoveAssignable, int> Pair;116 static_assert(std::is_nothrow_assignable<Tuple&, Pair&&>::value, "");117 static_assert(!std::is_assignable<Tuple&, Pair const&&>::value, "");118 }119 {120 typedef std::tuple<PotentiallyThrowingMoveAssignable, long> Tuple;121 typedef std::pair<PotentiallyThrowingMoveAssignable, int> Pair;122 static_assert(std::is_assignable<Tuple&, Pair&&>::value, "");123 static_assert(!std::is_nothrow_assignable<Tuple&, Pair&&>::value, "");124 static_assert(!std::is_assignable<Tuple&, Pair const&&>::value, "");125 }126 {127 // We assign through the reference and don't move out of the incoming ref,128 // so this doesn't work (but would if the type were CopyAssignable).129 {130 using T = std::tuple<MoveAssignable&, int>;131 using P = std::pair<MoveAssignable&, int>;132 static_assert(!std::is_assignable<T&, P&&>::value, "");133 }134 135 // ... works if it's CopyAssignable136 {137 using T = std::tuple<CopyAssignable&, int>;138 using P = std::pair<CopyAssignable&, int>;139 static_assert(std::is_assignable<T&, P&&>::value, "");140 }141 142 // For rvalue-references, we can move-assign if the type is MoveAssignable143 // or CopyAssignable (since in the worst case the move will decay into a copy).144 {145 using T1 = std::tuple<MoveAssignable&&, int>;146 using P1 = std::pair<MoveAssignable&&, int>;147 static_assert(std::is_assignable<T1&, P1&&>::value, "");148 149 using T2 = std::tuple<CopyAssignable&&, int>;150 using P2 = std::pair<CopyAssignable&&, int>;151 static_assert(std::is_assignable<T2&, P2&&>::value, "");152 }153 154 // In all cases, we can't move-assign if the types are not assignable,155 // since we assign through the reference.156 {157 using T1 = std::tuple<NonAssignable&, int>;158 using P1 = std::pair<NonAssignable&, int>;159 static_assert(!std::is_assignable<T1&, P1&&>::value, "");160 161 using T2 = std::tuple<NonAssignable&&, int>;162 using P2 = std::pair<NonAssignable&&, int>;163 static_assert(!std::is_assignable<T2&, P2&&>::value, "");164 }165 }166 {167 // Make sure that we don't incorrectly move out of the source's reference.168 using Dest = std::tuple<TrackMove, int>;169 using Source = std::pair<TrackMove&, int>;170 TrackMove track{3};171 Source src(track, 4);172 assert(!track.moved_from);173 174 Dest dst;175 dst = std::move(src); // here we should make a copy176 assert(!track.moved_from);177 assert(std::get<0>(dst).value == 3);178 }179 {180 // But we do move out of the source's reference if it's a rvalue ref181 using Dest = std::tuple<TrackMove, int>;182 using Source = std::pair<TrackMove&&, int>;183 TrackMove track{3};184 Source src(std::move(track), 4);185 assert(!track.moved_from); // we just took a reference186 187 Dest dst;188 dst = std::move(src);189 assert(track.moved_from);190 assert(std::get<0>(dst).value == 3);191 }192 {193 // If the pair holds a value, then we move out of it too194 using Dest = std::tuple<TrackMove, int>;195 using Source = std::pair<TrackMove, int>;196 Source src(TrackMove{3}, 4);197 Dest dst;198 dst = std::move(src);199 assert(src.first.moved_from);200 assert(std::get<0>(dst).value == 3);201 }202 203 return 0;204}205