86 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... UTypes>12// constexpr const tuple& operator=(const tuple<UTypes...>& u) const;13//14// Constraints:15// - sizeof...(Types) equals sizeof...(UTypes) and16// - (is_assignable_v<const Types&, const UTypes&> && ...) is true.17 18// UNSUPPORTED: c++03, c++11, c++14, c++17, c++2019 20#include <cassert>21#include <tuple>22#include <type_traits>23 24#include "test_macros.h"25#include "copy_move_types.h"26 27// test constraints28 29// sizeof...(Types) equals sizeof...(UTypes)30static_assert(std::is_assignable_v<const std::tuple<int&>&, const std::tuple<long&>&>);31static_assert(!std::is_assignable_v<const std::tuple<int&, int&>&, const std::tuple<long&>&>);32static_assert(!std::is_assignable_v<const std::tuple<int&>&, const std::tuple<long&, long&>&>);33 34// (is_assignable_v<const Types&, const UTypes&> && ...) is true35static_assert(std::is_assignable_v<const std::tuple<AssignableFrom<ConstCopyAssign>>&,36 const std::tuple<ConstCopyAssign>&>);37 38static_assert(std::is_assignable_v<const std::tuple<AssignableFrom<ConstCopyAssign>, ConstCopyAssign>&,39 const std::tuple<ConstCopyAssign, ConstCopyAssign>&>);40 41static_assert(!std::is_assignable_v<const std::tuple<AssignableFrom<ConstCopyAssign>, CopyAssign>&,42 const std::tuple<ConstCopyAssign, CopyAssign>&>);43 44constexpr bool test() {45 // reference types46 {47 int i1 = 1;48 int i2 = 2;49 long j1 = 3;50 long j2 = 4;51 const std::tuple<int&, int&> t1{i1, i2};52 const std::tuple<long&, long&> t2{j1, j2};53 t2 = t1;54 assert(std::get<0>(t2) == 1);55 assert(std::get<1>(t2) == 2);56 }57 58 // user defined const copy assignment59 {60 const std::tuple<ConstCopyAssign> t1{1};61 const std::tuple<AssignableFrom<ConstCopyAssign>> t2{2};62 t2 = t1;63 assert(std::get<0>(t2).v.val == 1);64 }65 66 // make sure the right assignment operator of the type in the tuple is used67 {68 std::tuple<TracedAssignment> t1{};69 const std::tuple<AssignableFrom<TracedAssignment>> t2{};70 t2 = t1;71 assert(std::get<0>(t2).v.constCopyAssign == 1);72 }73 74 return true;75}76 77int main(int, char**) {78 test();79 80// gcc cannot have mutable member in constant expression81#if !defined(TEST_COMPILER_GCC)82 static_assert(test());83#endif84 return 0;85}86