1 //===----------------------------------------------------------------------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is dual licensed under the MIT and the University of Illinois Open
6 // Source Licenses. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9
10 // UNSUPPORTED: c++98, c++03
11
12 // <string>
13
14 // basic_string& operator=(basic_string&& c)
15 // noexcept(
16 // allocator_traits<allocator_type>::propagate_on_container_move_assignment::value ||
17 // allocator_traits<allocator_type>::is_always_equal::value); // C++17
18 //
19 // before C++17, we use the conforming extension
20 // noexcept(
21 // allocator_type::propagate_on_container_move_assignment::value &&
22 // is_nothrow_move_assignable<allocator_type>::value);
23
24 #include <string>
25 #include <cassert>
26
27 #include "test_macros.h"
28 #include "test_allocator.h"
29
30 template <class T>
31 struct some_alloc
32 {
33 typedef T value_type;
34 some_alloc(const some_alloc&);
35 };
36
37 template <class T>
38 struct some_alloc2
39 {
40 typedef T value_type;
41
some_alloc2some_alloc242 some_alloc2() {}
43 some_alloc2(const some_alloc2&);
deallocatesome_alloc244 void deallocate(void*, unsigned) {}
45
46 typedef std::false_type propagate_on_container_move_assignment;
47 typedef std::true_type is_always_equal;
48 };
49
50 template <class T>
51 struct some_alloc3
52 {
53 typedef T value_type;
54
some_alloc3some_alloc355 some_alloc3() {}
56 some_alloc3(const some_alloc3&);
deallocatesome_alloc357 void deallocate(void*, unsigned) {}
58
59 typedef std::false_type propagate_on_container_move_assignment;
60 typedef std::false_type is_always_equal;
61 };
62
main()63 int main()
64 {
65 {
66 typedef std::string C;
67 static_assert(std::is_nothrow_move_assignable<C>::value, "");
68 }
69 {
70 typedef std::basic_string<char, std::char_traits<char>, test_allocator<char>> C;
71 static_assert(!std::is_nothrow_move_assignable<C>::value, "");
72 }
73 {
74 typedef std::basic_string<char, std::char_traits<char>, some_alloc<char>> C;
75 #if TEST_STD_VER > 14
76 // if the allocators are always equal, then the move assignment can be noexcept
77 static_assert( std::is_nothrow_move_assignable<C>::value, "");
78 #else
79 static_assert(!std::is_nothrow_move_assignable<C>::value, "");
80 #endif
81 }
82 #if TEST_STD_VER > 14
83 {
84 // POCMA is false, always equal
85 typedef std::basic_string<char, std::char_traits<char>, some_alloc2<char>> C;
86 static_assert( std::is_nothrow_move_assignable<C>::value, "");
87 }
88 {
89 // POCMA is false, not always equal
90 typedef std::basic_string<char, std::char_traits<char>, some_alloc3<char>> C;
91 static_assert(!std::is_nothrow_move_assignable<C>::value, "");
92 }
93 #endif
94 }
95