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<input_iterator I1, sentinel_for<I1> S1, forward_iterator I2, sentinel_for<I2> S2,
15 //          class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
16 //   requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
17 //   constexpr I1 ranges::find_first_of(I1 first1, S1 last1, I2 first2, S2 last2,
18 //                                      Pred pred = {},
19 //                                      Proj1 proj1 = {}, Proj2 proj2 = {});
20 // template<input_range R1, forward_range R2,
21 //          class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
22 //   requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
23 //   constexpr borrowed_iterator_t<R1>
24 //     ranges::find_first_of(R1&& r1, R2&& r2,
25 //                           Pred pred = {},
26 //                           Proj1 proj1 = {}, Proj2 proj2 = {});
27 
28 #include <algorithm>
29 #include <array>
30 #include <functional>
31 #include <ranges>
32 
33 #include "almost_satisfies_types.h"
34 #include "boolean_testable.h"
35 #include "test_iterators.h"
36 
37 template <class Iter1, class Iter2 = int*, class Sent1 = Iter1, class Sent2 = Iter2>
38 concept HasFindFirstOfIt = requires(Iter1 iter1, Sent1 sent1, Iter2 iter2, Sent2 sent2) {
39                              std::ranges::find_first_of(iter1, sent1, iter2, sent2);
40                            };
41 
42 static_assert(HasFindFirstOfIt<int*>);
43 static_assert(!HasFindFirstOfIt<InputIteratorNotDerivedFrom>);
44 static_assert(!HasFindFirstOfIt<InputIteratorNotIndirectlyReadable>);
45 static_assert(!HasFindFirstOfIt<InputIteratorNotInputOrOutputIterator>);
46 static_assert(!HasFindFirstOfIt<int*, ForwardIteratorNotDerivedFrom>);
47 static_assert(!HasFindFirstOfIt<int*, ForwardIteratorNotIncrementable>);
48 static_assert(!HasFindFirstOfIt<int*, int*, SentinelForNotSemiregular>);
49 static_assert(!HasFindFirstOfIt<int*, int*, SentinelForNotWeaklyEqualityComparableWith>);
50 static_assert(!HasFindFirstOfIt<int*, int*, int*, SentinelForNotSemiregular>);
51 static_assert(!HasFindFirstOfIt<int*, int*, int*, SentinelForNotWeaklyEqualityComparableWith>);
52 static_assert(!HasFindFirstOfIt<int*, int**>); // not indirectly_comparable
53 
54 template <class Range1, class Range2 = UncheckedRange<int*>>
55 concept HasFindFirstOfR = requires(Range1 range1, Range2 range2) {
56                              std::ranges::find_first_of(range1, range2);
57                            };
58 
59 static_assert(HasFindFirstOfR<UncheckedRange<int*>>);
60 static_assert(!HasFindFirstOfR<InputRangeNotDerivedFrom>);
61 static_assert(!HasFindFirstOfR<InputRangeNotIndirectlyReadable>);
62 static_assert(!HasFindFirstOfR<InputRangeNotInputOrOutputIterator>);
63 static_assert(!HasFindFirstOfR<UncheckedRange<int*>, ForwardRangeNotDerivedFrom>);
64 static_assert(!HasFindFirstOfR<UncheckedRange<int*>, ForwardRangeNotIncrementable>);
65 static_assert(!HasFindFirstOfR<UncheckedRange<int*>, InputRangeNotSentinelSemiregular>);
66 static_assert(!HasFindFirstOfR<UncheckedRange<int*>, InputRangeNotSentinelEqualityComparableWith>);
67 static_assert(!HasFindFirstOfR<UncheckedRange<int*>, ForwardRangeNotSentinelSemiregular>);
68 static_assert(!HasFindFirstOfR<UncheckedRange<int*>, ForwardRangeNotSentinelEqualityComparableWith>);
69 static_assert(!HasFindFirstOfR<UncheckedRange<int*>, UncheckedRange<int**>>); // not indirectly_comparable
70 
71 template <int N1, int N2>
72 struct Data {
73   std::array<int, N1> input1;
74   std::array<int, N2> input2;
75   ptrdiff_t expected;
76 };
77 
78 template <class Iter1, class Sent1, class Iter2, class Sent2, int N1, int N2>
79 constexpr void test(Data<N1, N2> d) {
80   {
81     std::same_as<Iter1> decltype(auto) ret =
82         std::ranges::find_first_of(Iter1(d.input1.data()), Sent1(Iter1(d.input1.data() + d.input1.size())),
83                                    Iter2(d.input2.data()), Sent2(Iter2(d.input2.data() + d.input2.size())));
84     assert(base(ret) == d.input1.data() + d.expected);
85   }
86   {
87     auto range1 = std::ranges::subrange(Iter1(d.input1.data()), Sent1(Iter1(d.input1.data() + d.input1.size())));
88     auto range2 = std::ranges::subrange(Iter2(d.input2.data()), Sent2(Iter2(d.input2.data() + d.input2.size())));
89     std::same_as<Iter1> decltype(auto) ret = std::ranges::find_first_of(range1, range2);
90     assert(base(ret) == d.input1.data() + d.expected);
91   }
92 }
93 
94 template <class Iter1, class Sent1, class Iter2, class Sent2 = Iter2>
95 constexpr void test_iterators() {
96   // simple test
97   test<Iter1, Sent1, Iter2, Sent2, 4, 2>({.input1 = {1, 2, 3, 4}, .input2 = {2, 3}, .expected = 1});
98   // other elements from input2 are checked
99   test<Iter1, Sent1, Iter2, Sent2, 4, 2>({.input1 = {1, 2, 3, 4}, .input2 = {3, 2}, .expected = 1});
100   // an empty second range returns last
101   test<Iter1, Sent1, Iter2, Sent2, 4, 0>({.input1 = {1, 2, 3, 4}, .input2 = {}, .expected = 4});
102   // check that an empty first range works
103   test<Iter1, Sent1, Iter2, Sent2, 0, 1>({.input1 = {}, .input2 = {1}, .expected = 0});
104   // check both ranges empty works
105   test<Iter1, Sent1, Iter2, Sent2, 0, 0>({.input1 = {}, .input2 = {}, .expected = 0});
106   // the first element is checked properly
107   test<Iter1, Sent1, Iter2, Sent2, 5, 2>({.input1 = {5, 4, 3, 2, 1}, .input2 = {1, 5}, .expected = 0});
108   // the last element is checked properly
109   test<Iter1, Sent1, Iter2, Sent2, 5, 2>({.input1 = {5, 4, 3, 2, 1}, .input2 = {1, 6}, .expected = 4});
110   // no match, one-past-the-end iterator should be returned
111   test<Iter1, Sent1, Iter2, Sent2, 4, 4>({.input1 = {1, 3, 5, 7}, .input2 = {0, 2, 4, 6}, .expected = 4});
112   // input2 contains a single element
113   test<Iter1, Sent1, Iter2, Sent2, 4, 1>({.input1 = {1, 3, 5, 7}, .input2 = {1}, .expected = 0});
114 }
115 
116 template <class Iter1, class Sent1 = Iter1>
117 constexpr void test_iterators1() {
118   test_iterators<Iter1, Sent1, forward_iterator<int*>, sentinel_wrapper<forward_iterator<int*>>>();
119   test_iterators<Iter1, Sent1, forward_iterator<int*>>();
120   test_iterators<Iter1, Sent1, bidirectional_iterator<int*>>();
121   test_iterators<Iter1, Sent1, random_access_iterator<int*>>();
122   test_iterators<Iter1, Sent1, contiguous_iterator<int*>>();
123   test_iterators<Iter1, Sent1, int*>();
124 }
125 
126 constexpr bool test() {
127   test_iterators1<cpp20_input_iterator<int*>, sentinel_wrapper<cpp20_input_iterator<int*>>>();
128   test_iterators1<cpp17_input_iterator<int*>, sentinel_wrapper<cpp17_input_iterator<int*>>>();
129   test_iterators1<forward_iterator<int*>>();
130   test_iterators1<bidirectional_iterator<int*>>();
131   test_iterators1<random_access_iterator<int*>>();
132   test_iterators1<contiguous_iterator<int*>>();
133   test_iterators1<int*>();
134 
135   { // check that std::ranges::dangling is returned
136     [[maybe_unused]] std::same_as<std::ranges::dangling> decltype(auto) ret =
137         std::ranges::find_first_of(std::array {1}, std::array {1});
138   }
139 
140   { // check that the predicate is used
141     int a[] = {1, 2, 3, 4};
142     int b[] = {2};
143     {
144       auto ret = std::ranges::find_first_of(std::begin(a), std::end(a),
145                                             std::begin(b), std::end(b),
146                                             std::ranges::greater{});
147       assert(ret == a + 2);
148     }
149     {
150       auto ret = std::ranges::find_first_of(a, b, std::ranges::greater{});
151       assert(ret == a + 2);
152     }
153   }
154 
155   { // check that the projections are used
156     int a[] = {1, 2, 3, 4};
157     int b[] = {4};
158     {
159       auto ret = std::ranges::find_first_of(std::begin(a), std::end(a),
160                                             std::begin(b), std::end(b), {},
161                                             [](int i) { return i / 2; },
162                                             [](int i) { return i - 3; });
163       assert(ret == a + 1);
164     }
165     {
166       auto ret = std::ranges::find_first_of(a, b, {}, [](int i) { return i / 2; }, [](int i) { return i - 3; });
167       assert(ret == a + 1);
168     }
169   }
170 
171   { // check that std::invoke is used
172     struct S1 {
173       constexpr S1(int i_) : i(i_) {}
174       constexpr bool compare(int j) const { return j == i; }
175       constexpr const S1& identity() const { return *this; }
176       int i;
177     };
178     struct S2 {
179       constexpr S2(int i_) : i(i_) {}
180       int i;
181     };
182 
183     {
184       S1 a[] = {1, 2, 3, 4};
185       S2 b[] = {2, 3};
186       auto ret = std::ranges::find_first_of(std::begin(a), std::end(a),
187                                             std::begin(b), std::end(b), &S1::compare, &S1::identity, &S2::i);
188       assert(ret == a + 1);
189     }
190     {
191       S1 a[] = {1, 2, 3, 4};
192       S2 b[] = {2, 3};
193       auto ret = std::ranges::find_first_of(a, b, &S1::compare, &S1::identity, &S2::i);
194       assert(ret == a + 1);
195     }
196   }
197 
198   { // check that the implicit conversion to bool works
199     StrictComparable<int> a[] = {1, 2, 3, 4};
200     StrictComparable<int> b[] = {2, 3};
201     {
202       auto ret = std::ranges::find_first_of(a, std::end(a), b, std::end(b));
203       assert(ret == a + 1);
204     }
205     {
206       auto ret = std::ranges::find_first_of(a, b);
207       assert(ret == a + 1);
208     }
209   }
210 
211   { // check that the complexity requirements are met
212     int a[] = {1, 2, 3, 4};
213     int b[] = {2, 3};
214     {
215       int predCount = 0;
216       auto predCounter = [&](int, int) { ++predCount; return false; };
217       int proj1Count = 0;
218       auto proj1Counter = [&](int i) { ++proj1Count; return i; };
219       int proj2Count = 0;
220       auto proj2Counter = [&](int i) { ++proj2Count; return i; };
221       auto ret = std::ranges::find_first_of(std::begin(a), std::end(a),
222                                             std::begin(b), std::end(b), predCounter, proj1Counter, proj2Counter);
223       assert(ret == a + 4);
224       assert(predCount <= 8);
225       assert(proj1Count <= 8);
226       assert(proj2Count <= 8);
227     }
228     {
229       int predCount = 0;
230       auto predCounter = [&](int, int) { ++predCount; return false; };
231       int proj1Count = 0;
232       auto proj1Counter = [&](int i) { ++proj1Count; return i; };
233       int proj2Count = 0;
234       auto proj2Counter = [&](int i) { ++proj2Count; return i; };
235       auto ret = std::ranges::find_first_of(a, b, predCounter, proj1Counter, proj2Counter);
236       assert(ret == a + 4);
237       assert(predCount == 8);
238       assert(proj1Count == 8);
239       assert(proj2Count == 8);
240     }
241   }
242 
243   return true;
244 }
245 
246 int main(int, char**) {
247   test();
248   static_assert(test());
249 
250   return 0;
251 }
252