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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 // test move
11 
12 // UNSUPPORTED: c++98, c++03
13 
14 #include <utility>
15 #include <type_traits>
16 #include <cassert>
17 
18 #include "test_macros.h"
19 
20 class move_only
21 {
22     move_only(const move_only&);
23     move_only& operator=(const move_only&);
24 public:
move_only(move_only &&)25     move_only(move_only&&) {}
operator =(move_only &&)26     move_only& operator=(move_only&&) {return *this;}
27 
move_only()28     move_only() {}
29 };
30 
source()31 move_only source() {return move_only();}
csource()32 const move_only csource() {return move_only();}
33 
test(move_only)34 void test(move_only) {}
35 
36 int x = 42;
37 const int& cx = x;
38 
39 template <class QualInt>
get()40 QualInt get() noexcept { return static_cast<QualInt>(x); }
41 
42 
43 int copy_ctor = 0;
44 int move_ctor = 0;
45 
46 struct A {
AA47     A() {}
AA48     A(const A&) {++copy_ctor;}
AA49     A(A&&) {++move_ctor;}
50     A& operator=(const A&) = delete;
51 };
52 
test_constexpr_move()53 constexpr bool test_constexpr_move() {
54 #if TEST_STD_VER > 11
55     int y = 42;
56     const int cy = y;
57     return std::move(y) == 42
58         && std::move(cy) == 42
59         && std::move(static_cast<int&&>(y)) == 42
60         && std::move(static_cast<int const&&>(y)) == 42;
61 #else
62     return true;
63 #endif
64 }
65 
main()66 int main()
67 {
68     { // Test return type and noexcept.
69         static_assert(std::is_same<decltype(std::move(x)), int&&>::value, "");
70         static_assert(noexcept(std::move(x)), "");
71         static_assert(std::is_same<decltype(std::move(cx)), const int&&>::value, "");
72         static_assert(noexcept(std::move(cx)), "");
73         static_assert(std::is_same<decltype(std::move(42)), int&&>::value, "");
74         static_assert(noexcept(std::move(42)), "");
75         static_assert(std::is_same<decltype(std::move(get<const int&&>())), const int&&>::value, "");
76         static_assert(noexcept(std::move(get<int const&&>())), "");
77     }
78     { // test copy and move semantics
79         A a;
80         const A ca = A();
81 
82         assert(copy_ctor == 0);
83         assert(move_ctor == 0);
84 
85         A a2 = a;
86         assert(copy_ctor == 1);
87         assert(move_ctor == 0);
88 
89         A a3 = std::move(a);
90         assert(copy_ctor == 1);
91         assert(move_ctor == 1);
92 
93         A a4 = ca;
94         assert(copy_ctor == 2);
95         assert(move_ctor == 1);
96 
97         A a5 = std::move(ca);
98         assert(copy_ctor == 3);
99         assert(move_ctor == 1);
100     }
101     { // test on a move only type
102         move_only mo;
103         test(std::move(mo));
104         test(source());
105     }
106 #if TEST_STD_VER > 11
107     {
108         constexpr int y = 42;
109         static_assert(std::move(y) == 42, "");
110         static_assert(test_constexpr_move(), "");
111     }
112 #endif
113 #if TEST_STD_VER == 11 && defined(_LIBCPP_VERSION)
114     // Test that std::forward is constexpr in C++11. This is an extension
115     // provided by both libc++ and libstdc++.
116     {
117         constexpr int y = 42;
118         static_assert(std::move(y) == 42, "");
119     }
120 #endif
121 }
122