xref: /llvm-project/libcxx/test/std/algorithms/alg.nonmodifying/alg.find/ranges.find.pass.cpp (revision f7407411a1dafb9464738d10cc9b64af04a21a8c)
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 
13 // ADDITIONAL_COMPILE_FLAGS(gcc-style-warnings): -Wno-sign-compare
14 // MSVC warning C4242: 'argument': conversion from 'const _Ty' to 'ElementT', possible loss of data
15 // MSVC warning C4244: 'argument': conversion from 'const _Ty' to 'ElementT', possible loss of data
16 // ADDITIONAL_COMPILE_FLAGS(cl-style-warnings): /wd4242 /wd4244
17 
18 // template<input_iterator I, sentinel_for<I> S, class T, class Proj = identity>
19 //   requires indirect_binary_predicate<ranges::equal_to, projected<I, Proj>, const T*>
20 //   constexpr I ranges::find(I first, S last, const T& value, Proj proj = {});
21 // template<input_range R, class T, class Proj = identity>
22 //   requires indirect_binary_predicate<ranges::equal_to, projected<iterator_t<R>, Proj>, const T*>
23 //   constexpr borrowed_iterator_t<R>
24 //     ranges::find(R&& r, const T& value, Proj proj = {});
25 
26 #include <algorithm>
27 #include <array>
28 #include <cassert>
29 #include <deque>
30 #include <ranges>
31 #include <vector>
32 
33 #include "almost_satisfies_types.h"
34 #include "test_iterators.h"
35 
36 struct NotEqualityComparable {};
37 
38 template <class It, class Sent = It>
39 concept HasFindIt = requires(It it, Sent sent) { std::ranges::find(it, sent, *it); };
40 static_assert(HasFindIt<int*>);
41 static_assert(!HasFindIt<NotEqualityComparable*>);
42 static_assert(!HasFindIt<InputIteratorNotDerivedFrom>);
43 static_assert(!HasFindIt<InputIteratorNotIndirectlyReadable>);
44 static_assert(!HasFindIt<InputIteratorNotInputOrOutputIterator>);
45 static_assert(!HasFindIt<cpp20_input_iterator<int*>, SentinelForNotSemiregular>);
46 static_assert(!HasFindIt<cpp20_input_iterator<int*>, InputRangeNotSentinelEqualityComparableWith>);
47 
48 static_assert(!HasFindIt<int*, int>);
49 static_assert(!HasFindIt<int, int*>);
50 
51 template <class Range, class ValT>
52 concept HasFindR = requires(Range r) { std::ranges::find(r, ValT{}); };
53 static_assert(HasFindR<std::array<int, 1>, int>);
54 static_assert(!HasFindR<int, int>);
55 static_assert(!HasFindR<std::array<NotEqualityComparable, 1>, NotEqualityComparable>);
56 static_assert(!HasFindR<InputRangeNotDerivedFrom, int>);
57 static_assert(!HasFindR<InputRangeNotIndirectlyReadable, int>);
58 static_assert(!HasFindR<InputRangeNotInputOrOutputIterator, int>);
59 static_assert(!HasFindR<InputRangeNotSentinelSemiregular, int>);
60 static_assert(!HasFindR<InputRangeNotSentinelEqualityComparableWith, int>);
61 
62 static std::vector<int> comparable_data;
63 
64 template <class It, class Sent = It>
test_iterators()65 constexpr void test_iterators() {
66   using ValueT = std::iter_value_t<It>;
67   { // simple test
68     {
69       ValueT a[] = {1, 2, 3, 4};
70       std::same_as<It> auto ret = std::ranges::find(It(a), Sent(It(a + 4)), 4);
71       assert(base(ret) == a + 3);
72       assert(*ret == 4);
73     }
74     {
75       ValueT a[] = {1, 2, 3, 4};
76       auto range = std::ranges::subrange(It(a), Sent(It(a + 4)));
77       std::same_as<It> auto ret = std::ranges::find(range, 4);
78       assert(base(ret) == a + 3);
79       assert(*ret == 4);
80     }
81   }
82 
83   { // check that an empty range works
84     {
85       std::array<ValueT, 0> a = {};
86       auto ret = std::ranges::find(It(a.data()), Sent(It(a.data())), 1);
87       assert(base(ret) == a.data());
88     }
89     {
90       std::array<ValueT, 0> a = {};
91       auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data())));
92       auto ret = std::ranges::find(range, 1);
93       assert(base(ret) == a.data());
94     }
95   }
96 
97   { // check that last is returned with no match
98     {
99       ValueT a[] = {1, 1, 1};
100       auto ret = std::ranges::find(a, a + 3, 0);
101       assert(ret == a + 3);
102     }
103     {
104       ValueT a[] = {1, 1, 1};
105       auto ret = std::ranges::find(a, 0);
106       assert(ret == a + 3);
107     }
108   }
109 
110   if (!std::is_constant_evaluated())
111     comparable_data.clear();
112 }
113 
114 template <class ElementT>
115 class TriviallyComparable {
116   ElementT el_;
117 
118 public:
TriviallyComparable(ElementT el)119   TEST_CONSTEXPR TriviallyComparable(ElementT el) : el_(el) {}
120   bool operator==(const TriviallyComparable&) const = default;
121 };
122 
test()123 constexpr bool test() {
124   types::for_each(types::type_list<char, wchar_t, int, long, TriviallyComparable<char>, TriviallyComparable<wchar_t>>{},
125                   []<class T> {
126                     types::for_each(types::cpp20_input_iterator_list<T*>{}, []<class Iter> {
127                       if constexpr (std::forward_iterator<Iter>)
128                         test_iterators<Iter>();
129                       test_iterators<Iter, sentinel_wrapper<Iter>>();
130                       test_iterators<Iter, sized_sentinel<Iter>>();
131                     });
132                   });
133 
134   // TODO: Remove the `_LIBCPP_ENABLE_EXPERIMENTAL` check once we have the FTM guarded or views::join isn't
135   // experimental anymore
136 #if TEST_STD_VER >= 20 && (!defined(_LIBCPP_VERSION) || defined(_LIBCPP_ENABLE_EXPERIMENTAL))
137   {
138     std::vector<std::vector<int>> vec = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};
139     auto view                         = vec | std::views::join;
140     assert(std::ranges::find(view.begin(), view.end(), 4) == std::next(view.begin(), 3));
141     assert(std::ranges::find(view, 4) == std::next(view.begin(), 3));
142   }
143 #endif
144 
145   { // check that the first element is returned
146     {
147       struct S {
148         int comp;
149         int other;
150       };
151       S a[] = { {0, 0}, {0, 2}, {0, 1} };
152       auto ret = std::ranges::find(a, 0, &S::comp);
153       assert(ret == a);
154       assert(ret->comp == 0);
155       assert(ret->other == 0);
156     }
157     {
158       struct S {
159         int comp;
160         int other;
161       };
162       S a[] = { {0, 0}, {0, 2}, {0, 1} };
163       auto ret = std::ranges::find(a, a + 3, 0, &S::comp);
164       assert(ret == a);
165       assert(ret->comp == 0);
166       assert(ret->other == 0);
167     }
168   }
169 
170   {
171     // check that an iterator is returned with a borrowing range
172     int a[] = {1, 2, 3, 4};
173     std::same_as<int*> auto ret = std::ranges::find(std::views::all(a), 1);
174     assert(ret == a);
175     assert(*ret == 1);
176   }
177 
178   {
179     // count invocations of the projection
180     {
181       int a[] = {1, 2, 3, 4};
182       int projection_count = 0;
183       auto ret = std::ranges::find(a, a + 4, 2, [&](int i) { ++projection_count; return i; });
184       assert(ret == a + 1);
185       assert(*ret == 2);
186       assert(projection_count == 2);
187     }
188     {
189       int a[] = {1, 2, 3, 4};
190       int projection_count = 0;
191       auto ret = std::ranges::find(a, 2, [&](int i) { ++projection_count; return i; });
192       assert(ret == a + 1);
193       assert(*ret == 2);
194       assert(projection_count == 2);
195     }
196   }
197 
198   return true;
199 }
200 
201 template <class IndexT>
202 class Comparable {
203   IndexT index_;
204 
205 public:
Comparable(IndexT i)206   Comparable(IndexT i)
207       : index_([&]() {
208           IndexT size = static_cast<IndexT>(comparable_data.size());
209           comparable_data.push_back(i);
210           return size;
211         }()) {}
212 
operator ==(const Comparable & other) const213   bool operator==(const Comparable& other) const {
214     return comparable_data[other.index_] == comparable_data[index_];
215   }
216 
operator ==(const Comparable & lhs,long long rhs)217   friend bool operator==(const Comparable& lhs, long long rhs) { return comparable_data[lhs.index_] == rhs; }
218 };
219 
test_deque()220 void test_deque() {
221   { // empty deque
222     std::deque<int> data;
223     assert(std::ranges::find(data, 4) == data.end());
224     assert(std::ranges::find(data.begin(), data.end(), 4) == data.end());
225   }
226 
227   { // single element - match
228     std::deque<int> data = {4};
229     assert(std::ranges::find(data, 4) == data.begin());
230     assert(std::ranges::find(data.begin(), data.end(), 4) == data.begin());
231   }
232 
233   { // single element - no match
234     std::deque<int> data = {3};
235     assert(std::ranges::find(data, 4) == data.end());
236     assert(std::ranges::find(data.begin(), data.end(), 4) == data.end());
237   }
238 
239   // many elements
240   for (auto size : {2, 3, 1023, 1024, 1025, 2047, 2048, 2049}) {
241     { // last element match
242       std::deque<int> data;
243       data.resize(size);
244       std::fill(data.begin(), data.end(), 3);
245       data[size - 1] = 4;
246       assert(std::ranges::find(data, 4) == data.end() - 1);
247       assert(std::ranges::find(data.begin(), data.end(), 4) == data.end() - 1);
248     }
249 
250     { // second-last element match
251       std::deque<int> data;
252       data.resize(size);
253       std::fill(data.begin(), data.end(), 3);
254       data[size - 2] = 4;
255       assert(std::ranges::find(data, 4) == data.end() - 2);
256       assert(std::ranges::find(data.begin(), data.end(), 4) == data.end() - 2);
257     }
258 
259     { // no match
260       std::deque<int> data;
261       data.resize(size);
262       std::fill(data.begin(), data.end(), 3);
263       assert(std::ranges::find(data, 4) == data.end());
264       assert(std::ranges::find(data.begin(), data.end(), 4) == data.end());
265     }
266   }
267 }
268 
main(int,char **)269 int main(int, char**) {
270   test_deque();
271   test();
272   static_assert(test());
273 
274   types::for_each(types::cpp20_input_iterator_list<Comparable<char>*>{}, []<class Iter> {
275     if constexpr (std::forward_iterator<Iter>)
276       test_iterators<Iter>();
277     test_iterators<Iter, sentinel_wrapper<Iter>>();
278     test_iterators<Iter, sized_sentinel<Iter>>();
279   });
280 
281   types::for_each(types::cpp20_input_iterator_list<Comparable<wchar_t>*>{}, []<class Iter> {
282     if constexpr (std::forward_iterator<Iter>)
283       test_iterators<Iter>();
284     test_iterators<Iter, sentinel_wrapper<Iter>>();
285     test_iterators<Iter, sized_sentinel<Iter>>();
286   });
287 
288   return 0;
289 }
290