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