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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03
// <string>
// basic_string& operator=(basic_string&& c)
// noexcept(
// allocator_traits<allocator_type>::propagate_on_container_move_assignment::value ||
// allocator_traits<allocator_type>::is_always_equal::value); // C++17, constexpr since C++20
//
// before C++17, we use the conforming extension
// noexcept(
// allocator_type::propagate_on_container_move_assignment::value &&
// is_nothrow_move_assignable<allocator_type>::value); // constexpr since C++20
#include <string>
#include <cassert>
#include "test_macros.h"
#include "test_allocator.h"
template <class T>
struct some_alloc {
typedef T value_type;
some_alloc(const some_alloc&);
T* allocate(std::size_t);
};
template <class T>
struct some_alloc2 {
typedef T value_type;
some_alloc2() {}
some_alloc2(const some_alloc2&);
T* allocate(std::size_t);
void deallocate(void*, unsigned) {}
typedef std::false_type propagate_on_container_move_assignment;
typedef std::true_type is_always_equal;
};
template <class T>
struct some_alloc3 {
typedef T value_type;
some_alloc3() {}
some_alloc3(const some_alloc3&);
T* allocate(std::size_t);
void deallocate(void*, unsigned) {}
typedef std::false_type propagate_on_container_move_assignment;
typedef std::false_type is_always_equal;
};
TEST_CONSTEXPR_CXX20 bool test() {
{
typedef std::string C;
static_assert(std::is_nothrow_move_assignable<C>::value, "");
}
{
typedef std::basic_string<char, std::char_traits<char>, test_allocator<char>> C;
static_assert(!std::is_nothrow_move_assignable<C>::value, "");
}
{
typedef std::basic_string<char, std::char_traits<char>, some_alloc<char>> C;
#if TEST_STD_VER > 14
// if the allocators are always equal, then the move assignment can be noexcept
static_assert(std::is_nothrow_move_assignable<C>::value, "");
#else
static_assert(!std::is_nothrow_move_assignable<C>::value, "");
#endif
}
#if TEST_STD_VER > 14
{
// POCMA is false, always equal
typedef std::basic_string<char, std::char_traits<char>, some_alloc2<char>> C;
static_assert(std::is_nothrow_move_assignable<C>::value, "");
}
{
// POCMA is false, not always equal
typedef std::basic_string<char, std::char_traits<char>, some_alloc3<char>> C;
static_assert(!std::is_nothrow_move_assignable<C>::value, "");
}
#endif
return true;
}
int main(int, char**) {
test();
#if TEST_STD_VER > 17
static_assert(test());
#endif
return 0;
}
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