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// <algorithm>
10
11// template<class ForwardIterator, class Size, class T, class BinaryPredicate>
12// constexpr ForwardIterator // constexpr after C++17
13// search_n(ForwardIterator first, ForwardIterator last, Size count,
14// const T& value, BinaryPredicate pred);
15
16#include <algorithm>
17#include <cassert>
18
19#include "test_macros.h"
20#include "test_iterators.h"
21#include "user_defined_integral.h"
22
23#if TEST_STD_VER > 17
24TEST_CONSTEXPR bool eq(int a, int b) { return a == b; }
25
26TEST_CONSTEXPR bool test_constexpr() {
27 int ia[] = {0, 0, 1, 1, 2, 2};
28 return (std::search_n(std::begin(ia), std::end(ia), 1, 0, eq) == ia)
29 && (std::search_n(std::begin(ia), std::end(ia), 2, 1, eq) == ia+2)
30 && (std::search_n(std::begin(ia), std::end(ia), 1, 3, eq) == std::end(ia))
31 ;
32 }
33#endif
34
35struct count_equal {
36 static unsigned count;
37 template <class T>
38 bool operator()(const T& x, const T& y) const {
39 ++count;
40 return x == y;
41 }
42};
43
44unsigned count_equal::count = 0;
45
46
47template <class Iter>
48void
49test()
50{
51 int ia[] = {0, 1, 2, 3, 4, 5};
52 const unsigned sa = sizeof(ia)/sizeof(ia[0]);
53 count_equal::count = 0;
54 assert(std::search_n(Iter(ia), Iter(ia+sa), 0, 0, count_equal()) == Iter(ia));
55 assert(count_equal::count <= sa);
56 count_equal::count = 0;
57 assert(std::search_n(Iter(ia), Iter(ia+sa), 1, 0, count_equal()) == Iter(ia+0));
58 assert(count_equal::count <= sa);
59 count_equal::count = 0;
60 assert(std::search_n(Iter(ia), Iter(ia+sa), 2, 0, count_equal()) == Iter(ia+sa));
61 assert(count_equal::count <= sa);
62 count_equal::count = 0;
63 assert(std::search_n(Iter(ia), Iter(ia+sa), sa, 0, count_equal()) == Iter(ia+sa));
64 assert(count_equal::count <= sa);
65 count_equal::count = 0;
66 assert(std::search_n(Iter(ia), Iter(ia+sa), 0, 3, count_equal()) == Iter(ia));
67 assert(count_equal::count <= sa);
68 count_equal::count = 0;
69 assert(std::search_n(Iter(ia), Iter(ia+sa), 1, 3, count_equal()) == Iter(ia+3));
70 assert(count_equal::count <= sa);
71 count_equal::count = 0;
72 assert(std::search_n(Iter(ia), Iter(ia+sa), 2, 3, count_equal()) == Iter(ia+sa));
73 assert(count_equal::count <= sa);
74 count_equal::count = 0;
75 assert(std::search_n(Iter(ia), Iter(ia+sa), sa, 3, count_equal()) == Iter(ia+sa));
76 assert(count_equal::count <= sa);
77 count_equal::count = 0;
78 assert(std::search_n(Iter(ia), Iter(ia+sa), 0, 5, count_equal()) == Iter(ia));
79 assert(count_equal::count <= sa);
80 count_equal::count = 0;
81 assert(std::search_n(Iter(ia), Iter(ia+sa), 1, 5, count_equal()) == Iter(ia+5));
82 assert(count_equal::count <= sa);
83 count_equal::count = 0;
84 assert(std::search_n(Iter(ia), Iter(ia+sa), 2, 5, count_equal()) == Iter(ia+sa));
85 assert(count_equal::count <= sa);
86 count_equal::count = 0;
87 assert(std::search_n(Iter(ia), Iter(ia+sa), sa, 5, count_equal()) == Iter(ia+sa));
88 assert(count_equal::count <= sa);
89 count_equal::count = 0;
90
91 int ib[] = {0, 0, 1, 1, 2, 2};
92 const unsigned sb = sizeof(ib)/sizeof(ib[0]);
93 assert(std::search_n(Iter(ib), Iter(ib+sb), 0, 0, count_equal()) == Iter(ib));
94 assert(count_equal::count <= sb);
95 count_equal::count = 0;
96 assert(std::search_n(Iter(ib), Iter(ib+sb), 1, 0, count_equal()) == Iter(ib+0));
97 assert(count_equal::count <= sb);
98 count_equal::count = 0;
99 assert(std::search_n(Iter(ib), Iter(ib+sb), 2, 0, count_equal()) == Iter(ib+0));
100 assert(count_equal::count <= sb);
101 count_equal::count = 0;
102 assert(std::search_n(Iter(ib), Iter(ib+sb), 3, 0, count_equal()) == Iter(ib+sb));
103 assert(count_equal::count <= sb);
104 count_equal::count = 0;
105 assert(std::search_n(Iter(ib), Iter(ib+sb), sb, 0, count_equal()) == Iter(ib+sb));
106 assert(count_equal::count <= sb);
107 count_equal::count = 0;
108 assert(std::search_n(Iter(ib), Iter(ib+sb), 0, 1, count_equal()) == Iter(ib));
109 assert(count_equal::count <= sb);
110 count_equal::count = 0;
111 assert(std::search_n(Iter(ib), Iter(ib+sb), 1, 1, count_equal()) == Iter(ib+2));
112 assert(count_equal::count <= sb);
113 count_equal::count = 0;
114 assert(std::search_n(Iter(ib), Iter(ib+sb), 2, 1, count_equal()) == Iter(ib+2));
115 assert(count_equal::count <= sb);
116 count_equal::count = 0;
117 assert(std::search_n(Iter(ib), Iter(ib+sb), 3, 1, count_equal()) == Iter(ib+sb));
118 assert(count_equal::count <= sb);
119 count_equal::count = 0;
120 assert(std::search_n(Iter(ib), Iter(ib+sb), sb, 1, count_equal()) == Iter(ib+sb));
121 assert(count_equal::count <= sb);
122 count_equal::count = 0;
123 assert(std::search_n(Iter(ib), Iter(ib+sb), 0, 2, count_equal()) == Iter(ib));
124 assert(count_equal::count <= sb);
125 count_equal::count = 0;
126 assert(std::search_n(Iter(ib), Iter(ib+sb), 1, 2, count_equal()) == Iter(ib+4));
127 assert(count_equal::count <= sb);
128 count_equal::count = 0;
129 assert(std::search_n(Iter(ib), Iter(ib+sb), 2, 2, count_equal()) == Iter(ib+4));
130 assert(count_equal::count <= sb);
131 count_equal::count = 0;
132 assert(std::search_n(Iter(ib), Iter(ib+sb), 3, 2, count_equal()) == Iter(ib+sb));
133 assert(count_equal::count <= sb);
134 count_equal::count = 0;
135 assert(std::search_n(Iter(ib), Iter(ib+sb), sb, 2, count_equal()) == Iter(ib+sb));
136 assert(count_equal::count <= sb);
137 count_equal::count = 0;
138
139 int ic[] = {0, 0, 0};
140 const unsigned sc = sizeof(ic)/sizeof(ic[0]);
141 assert(std::search_n(Iter(ic), Iter(ic+sc), 0, 0, count_equal()) == Iter(ic));
142 assert(count_equal::count <= sc);
143 count_equal::count = 0;
144 assert(std::search_n(Iter(ic), Iter(ic+sc), 1, 0, count_equal()) == Iter(ic));
145 assert(count_equal::count <= sc);
146 count_equal::count = 0;
147 assert(std::search_n(Iter(ic), Iter(ic+sc), 2, 0, count_equal()) == Iter(ic));
148 assert(count_equal::count <= sc);
149 count_equal::count = 0;
150 assert(std::search_n(Iter(ic), Iter(ic+sc), 3, 0, count_equal()) == Iter(ic));
151 assert(count_equal::count <= sc);
152 count_equal::count = 0;
153 assert(std::search_n(Iter(ic), Iter(ic+sc), 4, 0, count_equal()) == Iter(ic+sc));
154 assert(count_equal::count <= sc);
155 count_equal::count = 0;
156
157 // Check that we properly convert the size argument to an integral.
158 TEST_IGNORE_NODISCARD std::search_n(Iter(ic), Iter(ic+sc), UserDefinedIntegral<unsigned>(4), 0, count_equal());
159 count_equal::count = 0;
160}
161
162class A {
163public:
164 A(int x, int y) : x_(x), y_(y) {}
165 int x() const { return x_; }
166 int y() const { return y_; }
167
168private:
169 int x_;
170 int y_;
171};
172
173struct Pred {
174 bool operator()(const A& l, int r) const { return l.x() == r; }
175};
176
177int main(int, char**)
178{
179 test<forward_iterator<const int*> >();
180 test<bidirectional_iterator<const int*> >();
181 test<random_access_iterator<const int*> >();
182
183 // test bug reported in https://reviews.llvm.org/D124079?#3661721
184 {
185 A a[] = {A(1, 2), A(2, 3), A(2, 4)};
186 int value = 2;
187 auto result = std::search_n(first: a, last: a + 3, count: 1, val: value, binary_pred: Pred());
188 assert(result == a + 1);
189 }
190
191#if TEST_STD_VER > 17
192 static_assert(test_constexpr());
193#endif
194
195 return 0;
196}
197

source code of libcxx/test/std/algorithms/alg.nonmodifying/alg.search/search_n_pred.pass.cpp