1 //===----------------------------------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // UNSUPPORTED: c++98, c++03
14 // void swap(basic_string& c)
15 // noexcept(!allocator_type::propagate_on_container_swap::value ||
16 // __is_nothrow_swappable<allocator_type>::value);
18 // In C++17, the standard says that swap shall have:
19 // noexcept(allocator_traits<Allocator>::propagate_on_container_swap::value ||
20 // allocator_traits<Allocator>::is_always_equal::value);
22 // This tests a conforming extension
27 #include "test_macros.h"
28 #include "test_allocator.h"
36 some_alloc(const some_alloc&);
37 void deallocate(void*, unsigned) {}
39 typedef std::true_type propagate_on_container_swap;
48 some_alloc2(const some_alloc2&);
49 void deallocate(void*, unsigned) {}
51 typedef std::false_type propagate_on_container_swap;
52 typedef std::true_type is_always_equal;
58 typedef std::string C;
60 static_assert(noexcept(swap(c1, c2)), "");
63 typedef std::basic_string<char, std::char_traits<char>, test_allocator<char>> C;
65 static_assert(noexcept(swap(c1, c2)), "");
68 typedef std::basic_string<char, std::char_traits<char>, some_alloc<char>> C;
70 #if TEST_STD_VER >= 14
71 // In c++14, if POCS is set, swapping the allocator is required not to throw
72 static_assert( noexcept(swap(c1, c2)), "");
74 static_assert(!noexcept(swap(c1, c2)), "");
77 #if TEST_STD_VER >= 14
79 typedef std::basic_string<char, std::char_traits<char>, some_alloc2<char>> C;
81 // if the allocators are always equal, then the swap can be noexcept
82 static_assert( noexcept(swap(c1, c2)), "");