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-exception
6 //
7 //===----------------------------------------------------------------------===//
8
9 // UNSUPPORTED: c++03 && !stdlib=libc++
10
11 // <algorithm>
12
13 // template<BidirectionalIterator InIter, BidirectionalIterator OutIter>
14 // requires OutputIterator<OutIter, RvalueOf<InIter::reference>::type>
15 // OutIter
16 // move_backward(InIter first, InIter last, OutIter result);
17
18 #include <algorithm>
19 #include <cassert>
20 #include <iterator>
21 #include <memory>
22
23 #include "MoveOnly.h"
24 #include "test_iterators.h"
25 #include "test_macros.h"
26
27 class PaddedBase {
28 public:
PaddedBase(std::int16_t a,std::int8_t b)29 TEST_CONSTEXPR PaddedBase(std::int16_t a, std::int8_t b) : a_(a), b_(b) {}
30
31 std::int16_t a_;
32 std::int8_t b_;
33 };
34
35 class Derived : public PaddedBase {
36 public:
Derived(std::int16_t a,std::int8_t b,std::int8_t c)37 TEST_CONSTEXPR Derived(std::int16_t a, std::int8_t b, std::int8_t c) : PaddedBase(a, b), c_(c) {}
38
39 std::int8_t c_;
40 };
41
42 template <class InIter>
43 struct Test {
44 template <class OutIter>
operator ()Test45 TEST_CONSTEXPR_CXX20 void operator()() {
46 const unsigned N = 1000;
47 int ia[N] = {};
48 for (unsigned i = 0; i < N; ++i)
49 ia[i] = i;
50 int ib[N] = {0};
51
52 OutIter r = std::move_backward(InIter(ia), InIter(ia+N), OutIter(ib+N));
53 assert(base(r) == ib);
54 for (unsigned i = 0; i < N; ++i)
55 assert(ia[i] == ib[i]);
56 }
57 };
58
59 struct TestOutIters {
60 template <class InIter>
operator ()TestOutIters61 TEST_CONSTEXPR_CXX20 void operator()() {
62 types::for_each(
63 types::concatenate_t<types::bidirectional_iterator_list<int*> >(),
64 Test<InIter>());
65 }
66 };
67
68 template <class InIter>
69 struct Test1 {
70 template <class OutIter>
operator ()Test171 TEST_CONSTEXPR_CXX23 void operator()() {
72 const unsigned N = 100;
73 std::unique_ptr<int> ia[N];
74 for (unsigned i = 0; i < N; ++i)
75 ia[i].reset(new int(i));
76 std::unique_ptr<int> ib[N];
77
78 OutIter r = std::move_backward(InIter(ia), InIter(ia+N), OutIter(ib+N));
79 assert(base(r) == ib);
80 for (unsigned i = 0; i < N; ++i)
81 assert(*ib[i] == static_cast<int>(i));
82 }
83 };
84
85 struct Test1OutIters {
86 template <class InIter>
operator ()Test1OutIters87 TEST_CONSTEXPR_CXX23 void operator()() {
88 types::for_each(types::concatenate_t<types::bidirectional_iterator_list<std::unique_ptr<int>*> >(),
89 Test1<InIter>());
90 }
91 };
92
test()93 TEST_CONSTEXPR_CXX20 bool test() {
94 types::for_each(types::bidirectional_iterator_list<int*>(), TestOutIters());
95 if (TEST_STD_AT_LEAST_23_OR_RUNTIME_EVALUATED)
96 types::for_each(types::bidirectional_iterator_list<std::unique_ptr<int>*>(), Test1OutIters());
97
98 { // Make sure that padding bits aren't copied
99 Derived src(1, 2, 3);
100 Derived dst(4, 5, 6);
101 std::move_backward(
102 static_cast<PaddedBase*>(&src), static_cast<PaddedBase*>(&src) + 1, static_cast<PaddedBase*>(&dst) + 1);
103 assert(dst.a_ == 1);
104 assert(dst.b_ == 2);
105 assert(dst.c_ == 6);
106 }
107
108 { // Make sure that overlapping ranges can be copied
109 int a[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
110 std::move_backward(a, a + 7, a + 10);
111 int expected[] = {1, 2, 3, 1, 2, 3, 4, 5, 6, 7};
112 assert(std::equal(a, a + 10, expected));
113 }
114
115 // Make sure that the algorithm works with move-only types
116 {
117 // When non-trivial
118 {
119 MoveOnly from[3] = {1, 2, 3};
120 MoveOnly to[3] = {};
121 std::move_backward(std::begin(from), std::end(from), std::end(to));
122 assert(to[0] == MoveOnly(1));
123 assert(to[1] == MoveOnly(2));
124 assert(to[2] == MoveOnly(3));
125 }
126 // When trivial
127 {
128 TrivialMoveOnly from[3] = {1, 2, 3};
129 TrivialMoveOnly to[3] = {};
130 std::move_backward(std::begin(from), std::end(from), std::end(to));
131 assert(to[0] == TrivialMoveOnly(1));
132 assert(to[1] == TrivialMoveOnly(2));
133 assert(to[2] == TrivialMoveOnly(3));
134 }
135 }
136
137 return true;
138 }
139
main(int,char **)140 int main(int, char**)
141 {
142 test();
143 #if TEST_STD_VER >= 20
144 static_assert(test());
145 #endif
146
147 return 0;
148 }
149