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
27class PaddedBase {
28public:
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
35class Derived : public PaddedBase {
36public:
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
42template <class InIter>
43struct Test {
44 template <class OutIter>
45 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
59struct TestOutIters {
60 template <class InIter>
61 TEST_CONSTEXPR_CXX20 void operator()() {
62 types::for_each(
63 types::concatenate_t<types::bidirectional_iterator_list<int*> >(),
64 Test<InIter>());
65 }
66};
67
68template <class InIter>
69struct Test1 {
70 template <class OutIter>
71 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(p: 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
85struct Test1OutIters {
86 template <class InIter>
87 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
93TEST_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 first: static_cast<PaddedBase*>(&src), last: static_cast<PaddedBase*>(&src) + 1, result: 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(first: a, last: a + 7, result: 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
140int main(int, char**)
141{
142 test();
143#if TEST_STD_VER >= 20
144 static_assert(test());
145#endif
146
147 return 0;
148}
149

source code of libcxx/test/std/algorithms/alg.modifying.operations/alg.move/move_backward.pass.cpp