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 // UNSUPPORTED: c++03, c++11, c++14, c++17 12 // UNSUPPORTED: libcpp-has-no-incomplete-ranges 13 14 // template<forward_iterator I, sentinel_for<I> S, class T, 15 // class Pred = ranges::equal_to, class Proj = identity> 16 // requires indirectly_comparable<I, const T*, Pred, Proj> 17 // constexpr subrange<I> 18 // ranges::search_n(I first, S last, iter_difference_t<I> count, 19 // const T& value, Pred pred = {}, Proj proj = {}); 20 // template<forward_range R, class T, class Pred = ranges::equal_to, 21 // class Proj = identity> 22 // requires indirectly_comparable<iterator_t<R>, const T*, Pred, Proj> 23 // constexpr borrowed_subrange_t<R> 24 // ranges::search_n(R&& r, range_difference_t<R> count, 25 // const T& value, Pred pred = {}, Proj proj = {}); 26 27 #include <algorithm> 28 #include <array> 29 #include <ranges> 30 31 #include "almost_satisfies_types.h" 32 #include "test_iterators.h" 33 34 template <class Iter1, class Sent1 = Iter1> 35 concept HasSearchNIt = requires (Iter1 first1, Sent1 last1) { 36 std::ranges::search_n(first1, last1, 0, 0); 37 }; 38 39 static_assert(HasSearchNIt<int*>); 40 static_assert(!HasSearchNIt<ForwardIteratorNotDerivedFrom>); 41 static_assert(!HasSearchNIt<ForwardIteratorNotIncrementable>); 42 static_assert(!HasSearchNIt<int*, SentinelForNotSemiregular>); 43 static_assert(!HasSearchNIt<int*, SentinelForNotWeaklyEqualityComparableWith>); 44 static_assert(!HasSearchNIt<int**, int**>); // not indirectly comparable 45 46 template <class Range1, class Range2 = UncheckedRange<int*>> 47 concept HasSearchNR = requires (Range1 range) { 48 std::ranges::search_n(range, 0, 0); 49 }; 50 51 static_assert(HasSearchNR<UncheckedRange<int*>>); 52 static_assert(!HasSearchNR<ForwardRangeNotDerivedFrom>); 53 static_assert(!HasSearchNR<ForwardIteratorNotIncrementable>); 54 static_assert(!HasSearchNR<ForwardRangeNotSentinelSemiregular>); 55 static_assert(!HasSearchNR<ForwardRangeNotSentinelEqualityComparableWith>); 56 static_assert(!HasSearchNR<UncheckedRange<int**>>); // not indirectly comparable 57 58 template <class Iter, class Sent = Iter> 59 constexpr void test_iterators() { 60 { // simple test 61 { 62 int a[] = {1, 2, 3, 4, 5, 6}; 63 std::same_as<std::ranges::subrange<Iter, Iter>> decltype(auto) ret = 64 std::ranges::search_n(Iter(a), Sent(Iter(a + 6)), 1, 3); 65 assert(base(ret.begin()) == a + 2); 66 assert(base(ret.end()) == a + 3); 67 } 68 { 69 int a[] = {1, 2, 3, 4, 5, 6}; 70 auto range = std::ranges::subrange(Iter(a), Sent(Iter(a + 6))); 71 std::same_as<std::ranges::subrange<Iter, Iter>> decltype(auto) ret = std::ranges::search_n(range, 1, 3); 72 assert(base(ret.begin()) == a + 2); 73 assert(base(ret.end()) == a + 3); 74 } 75 } 76 77 { // matching part begins at the front 78 { 79 int a[] = {7, 7, 3, 7, 3, 6}; 80 auto ret = std::ranges::search_n(Iter(a), Sent(Iter(a + 6)), 2, 7); 81 assert(base(ret.begin()) == a); 82 assert(base(ret.end()) == a + 2); 83 } 84 { 85 int a[] = {7, 7, 3, 7, 3, 6}; 86 auto range = std::ranges::subrange(Iter(a), Sent(Iter(a + 6))); 87 auto ret = std::ranges::search_n(range, 2, 7); 88 assert(base(ret.begin()) == a); 89 assert(base(ret.end()) == a + 2); 90 } 91 } 92 93 { // matching part ends at the back 94 { 95 int a[] = {9, 3, 6, 4, 4}; 96 auto ret = std::ranges::search_n(Iter(a), Sent(Iter(a + 5)), 2, 4); 97 assert(base(ret.begin()) == a + 3); 98 assert(base(ret.end()) == a + 5); 99 } 100 { 101 int a[] = {9, 3, 6, 4, 4}; 102 auto range = std::ranges::subrange(Iter(a), Sent(Iter(a + 5))); 103 auto ret = std::ranges::search_n(range, 2, 4); 104 assert(base(ret.begin()) == a + 3); 105 assert(base(ret.end()) == a + 5); 106 } 107 } 108 109 { // pattern does not match 110 { 111 int a[] = {9, 3, 6, 4, 8}; 112 auto ret = std::ranges::search_n(Iter(a), Sent(Iter(a + 5)), 1, 1); 113 assert(base(ret.begin()) == a + 5); 114 assert(base(ret.end()) == a + 5); 115 } 116 { 117 int a[] = {9, 3, 6, 4, 8}; 118 auto range = std::ranges::subrange(Iter(a), Sent(Iter(a + 5))); 119 auto ret = std::ranges::search_n(range, 1, 1); 120 assert(base(ret.begin()) == a + 5); 121 assert(base(ret.end()) == a + 5); 122 } 123 } 124 125 { // range and pattern are identical 126 { 127 int a[] = {1, 1, 1, 1}; 128 auto ret = std::ranges::search_n(Iter(a), Sent(Iter(a + 4)), 4, 1); 129 assert(base(ret.begin()) == a); 130 assert(base(ret.end()) == a + 4); 131 } 132 { 133 int a[] = {1, 1, 1, 1}; 134 auto range = std::ranges::subrange(Iter(a), Sent(Iter(a + 4))); 135 auto ret = std::ranges::search_n(range, 4, 1); 136 assert(base(ret.begin()) == a); 137 assert(base(ret.end()) == a + 4); 138 } 139 } 140 141 { // pattern is longer than range 142 { 143 int a[] = {3, 3, 3}; 144 auto ret = std::ranges::search_n(Iter(a), Sent(Iter(a + 3)), 4, 3); 145 assert(base(ret.begin()) == a + 3); 146 assert(base(ret.end()) == a + 3); 147 } 148 { 149 int a[] = {3, 3, 3}; 150 auto range = std::ranges::subrange(Iter(a), Sent(Iter(a + 3))); 151 auto ret = std::ranges::search_n(range, 4, 3); 152 assert(base(ret.begin()) == a + 3); 153 assert(base(ret.end()) == a + 3); 154 } 155 } 156 157 { // pattern has zero length 158 { 159 int a[] = {6, 7, 8}; 160 auto ret = std::ranges::search_n(Iter(a), Sent(Iter(a + 3)), 0, 7); 161 assert(base(ret.begin()) == a); 162 assert(base(ret.end()) == a); 163 } 164 { 165 int a[] = {6, 7, 8}; 166 auto range = std::ranges::subrange(Iter(a), Sent(Iter(a + 3))); 167 auto ret = std::ranges::search_n(range, 0, 7); 168 assert(base(ret.begin()) == a); 169 assert(base(ret.end()) == a); 170 } 171 } 172 173 { // range has zero length 174 { 175 int a[] = {}; 176 auto ret = std::ranges::search_n(Iter(a), Sent(Iter(a)), 1, 1); 177 assert(base(ret.begin()) == a); 178 assert(base(ret.end()) == a); 179 } 180 { 181 int a[] = {}; 182 auto range = std::ranges::subrange(Iter(a), Sent(Iter(a))); 183 auto ret = std::ranges::search_n(range, 1, 1); 184 assert(base(ret.begin()) == a); 185 assert(base(ret.end()) == a); 186 } 187 } 188 189 { // check that the first match is returned 190 { 191 int a[] = {6, 6, 8, 6, 6, 8, 6, 6, 8}; 192 auto ret = std::ranges::search_n(Iter(a), Sent(Iter(a + 9)), 2, 6); 193 assert(base(ret.begin()) == a); 194 assert(base(ret.end()) == a + 2); 195 } 196 { 197 int a[] = {6, 6, 8, 6, 6, 8, 6, 6, 8}; 198 auto range = std::ranges::subrange(Iter(a), Sent(Iter(a + 9))); 199 auto ret = std::ranges::search_n(range, 2, 6); 200 assert(base(ret.begin()) == a); 201 assert(base(ret.end()) == a + 2); 202 } 203 } 204 205 { // check that the predicate is used 206 { 207 int a[] = {1, 4, 4, 3, 6, 1}; 208 auto ret = std::ranges::search_n(Iter(a), Sent(Iter(a + 6)), 209 3, 210 4, 211 [](int l, int r) { return l == r || l == 1; }); 212 assert(base(ret.begin()) == a); 213 assert(base(ret.end()) == a + 3); 214 } 215 { 216 int a[] = {1, 4, 4, 3, 6, 1}; 217 auto range = std::ranges::subrange(Iter(a), Sent(Iter(a + 6))); 218 auto ret = std::ranges::search_n(range, 3, 4, [](int l, int r) { return l == r || l == 1; }); 219 assert(base(ret.begin()) == a); 220 assert(base(ret.end()) == a + 3); 221 } 222 } 223 224 { // check that the projections are used 225 { 226 int a[] = {1, 3, 1, 6, 5, 6}; 227 auto ret = std::ranges::search_n(Iter(a), Sent(Iter(a + 6)), 228 3, 229 6, 230 {}, 231 [](int i) { return i % 2 == 0 ? i : i + 1; }); 232 assert(base(ret.begin()) == a + 3); 233 assert(base(ret.end()) == a + 6); 234 } 235 { 236 int a[] = {1, 3, 1, 6, 5, 6}; 237 auto range = std::ranges::subrange(Iter(a), Sent(Iter(a + 6))); 238 auto ret = std::ranges::search_n(range, 239 3, 240 6, 241 {}, 242 [](int i) { return i % 2 == 0 ? i : i + 1; }); 243 assert(base(ret.begin()) == a + 3); 244 assert(base(ret.end()) == a + 6); 245 } 246 } 247 } 248 constexpr bool test() { 249 test_iterators<forward_iterator<int*>>(); 250 test_iterators<forward_iterator<int*>, sized_sentinel<forward_iterator<int*>>>(); 251 test_iterators<bidirectional_iterator<int*>>(); 252 test_iterators<bidirectional_iterator<int*>, sized_sentinel<bidirectional_iterator<int*>>>(); 253 test_iterators<random_access_iterator<int*>>(); 254 test_iterators<random_access_iterator<int*>, sized_sentinel<random_access_iterator<int*>>>(); 255 test_iterators<contiguous_iterator<int*>>(); 256 test_iterators<contiguous_iterator<int*>, sized_sentinel<contiguous_iterator<int*>>>(); 257 test_iterators<int*>(); 258 259 { // check that std::invoke is used 260 struct S { 261 int i; 262 263 constexpr S identity() { 264 return *this; 265 } 266 267 constexpr bool compare(int o) { 268 return i == o; 269 } 270 }; 271 { 272 S a[] = {{1}, {2}, {3}, {4}}; 273 auto ret = std::ranges::search_n(a, a + 4, 1, 2, &S::compare, &S::identity); 274 assert(ret.begin() == a + 1); 275 assert(ret.end() == a + 2); 276 } 277 { 278 S a[] = {{1}, {2}, {3}, {4}}; 279 auto ret = std::ranges::search_n(a, 1, 2, &S::compare, &S::identity); 280 assert(ret.begin() == a + 1); 281 assert(ret.end() == a + 2); 282 } 283 } 284 285 { // check that std::ranges::dangling is returned 286 [[maybe_unused]] std::same_as<std::ranges::dangling> decltype(auto) ret = 287 std::ranges::search_n(std::array {1, 2, 3, 4}, 1, 0); 288 } 289 290 return true; 291 } 292 293 int main(int, char**) { 294 test(); 295 static_assert(test()); 296 297 return 0; 298 } 299