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, c++11, c++14, c++17
10
11 // <algorithm>
12
13 // template<class ForwardIterator>
14 // constexpr ForwardIterator
15 // shift_left(ForwardIterator first, ForwardIterator last,
16 // typename iterator_traits<ForwardIterator>::difference_type n);
17
18 #include <algorithm>
19 #include <cassert>
20
21 #include "test_macros.h"
22 #include "test_iterators.h"
23 #include "MoveOnly.h"
24
25 template<class T, class Iter>
test()26 constexpr bool test()
27 {
28 int orig[] = {3,1,4,1,5, 9,2,6,5,3, 5,8,9,7,9};
29 T work[] = {3,1,4,1,5, 9,2,6,5,3, 5,8,9,7,9};
30
31 for (int n = 0; n <= 15; ++n) {
32 for (int k = 0; k <= n+2; ++k) {
33 std::copy(orig, orig+n, work);
34 Iter it = std::shift_left(Iter(work), Iter(work+n), k);
35 if (0 <= k && k < n) {
36 assert(it == Iter(work+n-k));
37 assert(std::equal(orig+k, orig+n, work, work+n-k));
38 } else {
39 assert(it == Iter(work));
40 assert(std::equal(orig, orig+n, work, work+n));
41 }
42 }
43 }
44
45 // n == 0
46 {
47 T input[] = { 0, 1, 2 };
48 const T expected[] = { 0, 1, 2 };
49 Iter b = Iter(std::begin(input));
50 Iter e = Iter(std::end(input));
51 Iter it = std::shift_left(b, e, 0);
52 assert(std::equal(std::begin(expected), std::end(expected), b, e));
53 assert(it == e);
54 }
55
56 // n > 0 && n < len
57 {
58 T input[] = { 0, 1, 2 };
59 const T expected[] = { 1, 2 };
60 Iter b = Iter(std::begin(input));
61 Iter e = Iter(std::end(input));
62 Iter it = std::shift_left(b, e, 1);
63 assert(std::equal(std::begin(expected), std::end(expected), b, it));
64 }
65 {
66 T input[] = { 1, 2, 3, 4, 5, 6, 7, 8 };
67 const T expected[] = { 3, 4, 5, 6, 7, 8 };
68 Iter b = Iter(std::begin(input));
69 Iter e = Iter(std::end(input));
70 Iter it = std::shift_left(b, e, 2);
71 assert(std::equal(std::begin(expected), std::end(expected), b, it));
72 }
73 {
74 T input[] = { 1, 2, 3, 4, 5, 6, 7, 8 };
75 const T expected[] = { 7, 8 };
76 Iter b = Iter(std::begin(input));
77 Iter e = Iter(std::end(input));
78 Iter it = std::shift_left(b, e, 6);
79 assert(std::equal(std::begin(expected), std::end(expected), b, it));
80 }
81
82 // n == len
83 {
84 T input[] = { 0, 1, 2 };
85 const T expected[] = { 0, 1, 2 };
86 Iter b = Iter(std::begin(input));
87 Iter e = Iter(std::end(input));
88 Iter it = std::shift_left(b, e, std::size(input));
89 assert(std::equal(std::begin(expected), std::end(expected), b, e));
90 assert(it == b);
91 }
92
93 // n > len
94 {
95 T input[] = { 0, 1, 2 };
96 const T expected[] = { 0, 1, 2 };
97 Iter b = Iter(std::begin(input));
98 Iter e = Iter(std::end(input));
99 Iter it = std::shift_left(b, e, std::size(input) + 1);
100 assert(std::equal(std::begin(expected), std::end(expected), b, e));
101 assert(it == b);
102 }
103
104 return true;
105 }
106
main(int,char **)107 int main(int, char**)
108 {
109 test<int, forward_iterator<int*>>();
110 test<int, bidirectional_iterator<int*>>();
111 test<int, random_access_iterator<int*>>();
112 test<int, int*>();
113 test<MoveOnly, forward_iterator<MoveOnly*>>();
114 test<MoveOnly, bidirectional_iterator<MoveOnly*>>();
115 test<MoveOnly, random_access_iterator<MoveOnly*>>();
116 test<MoveOnly, MoveOnly*>();
117
118 static_assert(test<int, forward_iterator<int*>>());
119 static_assert(test<int, bidirectional_iterator<int*>>());
120 static_assert(test<int, random_access_iterator<int*>>());
121 static_assert(test<int, int*>());
122 static_assert(test<MoveOnly, forward_iterator<MoveOnly*>>());
123 static_assert(test<MoveOnly, bidirectional_iterator<MoveOnly*>>());
124 static_assert(test<MoveOnly, random_access_iterator<MoveOnly*>>());
125 static_assert(test<MoveOnly, MoveOnly*>());
126
127 return 0;
128 }
129