104 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// UNSUPPORTED: c++0310 11// <string>12 13// basic_string& operator=(basic_string&& c)14// noexcept(15// allocator_traits<allocator_type>::propagate_on_container_move_assignment::value ||16// allocator_traits<allocator_type>::is_always_equal::value); // C++17, constexpr since C++2017//18// before C++17, we use the conforming extension19// noexcept(20// allocator_type::propagate_on_container_move_assignment::value &&21// is_nothrow_move_assignable<allocator_type>::value); // constexpr since C++2022 23#include <string>24#include <cassert>25 26#include "test_macros.h"27#include "test_allocator.h"28 29template <class T>30struct some_alloc {31 typedef T value_type;32 some_alloc(const some_alloc&);33 T* allocate(std::size_t);34};35 36template <class T>37struct some_alloc2 {38 typedef T value_type;39 40 some_alloc2() {}41 some_alloc2(const some_alloc2&);42 T* allocate(std::size_t);43 void deallocate(void*, unsigned) {}44 45 typedef std::false_type propagate_on_container_move_assignment;46 typedef std::true_type is_always_equal;47};48 49template <class T>50struct some_alloc3 {51 typedef T value_type;52 53 some_alloc3() {}54 some_alloc3(const some_alloc3&);55 T* allocate(std::size_t);56 void deallocate(void*, unsigned) {}57 58 typedef std::false_type propagate_on_container_move_assignment;59 typedef std::false_type is_always_equal;60};61 62TEST_CONSTEXPR_CXX20 bool test() {63 {64 typedef std::string C;65 static_assert(std::is_nothrow_move_assignable<C>::value, "");66 }67 {68 typedef std::basic_string<char, std::char_traits<char>, test_allocator<char>> C;69 static_assert(!std::is_nothrow_move_assignable<C>::value, "");70 }71 {72 typedef std::basic_string<char, std::char_traits<char>, some_alloc<char>> C;73#if TEST_STD_VER > 1474 // if the allocators are always equal, then the move assignment can be noexcept75 static_assert(std::is_nothrow_move_assignable<C>::value, "");76#else77 static_assert(!std::is_nothrow_move_assignable<C>::value, "");78#endif79 }80#if TEST_STD_VER > 1481 {82 // POCMA is false, always equal83 typedef std::basic_string<char, std::char_traits<char>, some_alloc2<char>> C;84 static_assert(std::is_nothrow_move_assignable<C>::value, "");85 }86 {87 // POCMA is false, not always equal88 typedef std::basic_string<char, std::char_traits<char>, some_alloc3<char>> C;89 static_assert(!std::is_nothrow_move_assignable<C>::value, "");90 }91#endif92 93 return true;94}95 96int main(int, char**) {97 test();98#if TEST_STD_VER > 1799 static_assert(test());100#endif101 102 return 0;103}104