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 // <functional>
10 
11 // UNSUPPORTED: c++03, c++11, c++14
12 
13 // default searcher
14 // template<class _ForwardIterator, class _BinaryPredicate = equal_to<>>
15 // class default_searcher {
16 // public:
17 //     default_searcher(_ForwardIterator __f, _ForwardIterator __l,
18 //                             _BinaryPredicate __p = _BinaryPredicate())
19 //         : __first_(__f), __last_(__l), __pred_(__p) {}
20 //
21 //     template <typename _ForwardIterator2>
22 //     pair<_ForwardIterator2, _ForwardIterator2>
23 //     operator () (_ForwardIterator2 __f, _ForwardIterator2 __l) const {
24 //         return std::search(__f, __l, __first_, __last_, __pred_);
25 //         }
26 //
27 // private:
28 //     _ForwardIterator __first_;
29 //     _ForwardIterator __last_;
30 //     _BinaryPredicate __pred_;
31 //     };
32 
33 
34 #include <algorithm>
35 #include <functional>
36 #include <cassert>
37 
38 #include "test_macros.h"
39 #include "test_iterators.h"
40 
41 struct count_equal
42 {
43     int *count;
44 
45     template <class T>
46     TEST_CONSTEXPR_CXX14 bool operator()(const T& x, const T& y) const
47         {++*count; return x == y;}
48 };
49 
50 template <typename Iter1, typename Iter2>
51 TEST_CONSTEXPR_CXX20
52 void do_search(Iter1 b1, Iter1 e1, Iter2 b2, Iter2 e2, Iter1 result) {
53     int count = 0;
54     std::default_searcher<Iter2, count_equal> s{b2, e2, count_equal{&count}};
55     assert(result == std::search(b1, e1, s));
56     auto d1 = std::distance(b1, e1);
57     auto d2 = std::distance(b2, e2);
58     assert((count >= 1) || (d2 == 0) || (d1 < d2));
59     assert((d1 < d2) || count <= d1 * (d1 - d2 + 1));
60 }
61 
62 template <class Iter1, class Iter2>
63 TEST_CONSTEXPR_CXX20
64 bool test()
65 {
66     int ia[] = {0, 1, 2, 3, 4, 5};
67     const unsigned sa = sizeof(ia)/sizeof(ia[0]);
68     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia),      Iter2(ia),    Iter1(ia));
69     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia),      Iter2(ia+1),  Iter1(ia));
70     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia+1),    Iter2(ia+2),  Iter1(ia+1));
71     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia+2),    Iter2(ia+2),  Iter1(ia));
72     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia+2),    Iter2(ia+3),  Iter1(ia+2));
73     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia+2),    Iter2(ia+3),  Iter1(ia+2));
74     do_search(Iter1(ia), Iter1(ia),      Iter2(ia+2),    Iter2(ia+3),  Iter1(ia));
75     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia+sa-1), Iter2(ia+sa), Iter1(ia+sa-1));
76     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia+sa-3), Iter2(ia+sa), Iter1(ia+sa-3));
77     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia),      Iter2(ia+sa), Iter1(ia));
78     do_search(Iter1(ia), Iter1(ia+sa-1), Iter2(ia),      Iter2(ia+sa), Iter1(ia+sa-1));
79     do_search(Iter1(ia), Iter1(ia+1),    Iter2(ia),      Iter2(ia+sa), Iter1(ia+1));
80     int ib[] = {0, 1, 2, 0, 1, 2, 3, 0, 1, 2, 3, 4};
81     const unsigned sb = sizeof(ib)/sizeof(ib[0]);
82     int ic[] = {1};
83     do_search(Iter1(ib), Iter1(ib+sb), Iter2(ic), Iter2(ic+1), Iter1(ib+1));
84     int id[] = {1, 2};
85     do_search(Iter1(ib), Iter1(ib+sb), Iter2(id), Iter2(id+2), Iter1(ib+1));
86     int ie[] = {1, 2, 3};
87     do_search(Iter1(ib), Iter1(ib+sb), Iter2(ie), Iter2(ie+3), Iter1(ib+4));
88     int ig[] = {1, 2, 3, 4};
89     do_search(Iter1(ib), Iter1(ib+sb), Iter2(ig), Iter2(ig+4), Iter1(ib+8));
90     int ih[] = {0, 1, 1, 1, 1, 2, 3, 0, 1, 2, 3, 4};
91     const unsigned sh = sizeof(ih)/sizeof(ih[0]);
92     int ii[] = {1, 1, 2};
93     do_search(Iter1(ih), Iter1(ih+sh), Iter2(ii), Iter2(ii+3), Iter1(ih+3));
94 
95     return true;
96 }
97 
98 int main(int, char**) {
99     test<forward_iterator<const int*>, forward_iterator<const int*> >();
100     test<forward_iterator<const int*>, bidirectional_iterator<const int*> >();
101     test<forward_iterator<const int*>, random_access_iterator<const int*> >();
102     test<bidirectional_iterator<const int*>, forward_iterator<const int*> >();
103     test<bidirectional_iterator<const int*>, bidirectional_iterator<const int*> >();
104     test<bidirectional_iterator<const int*>, random_access_iterator<const int*> >();
105     test<random_access_iterator<const int*>, forward_iterator<const int*> >();
106     test<random_access_iterator<const int*>, bidirectional_iterator<const int*> >();
107     test<random_access_iterator<const int*>, random_access_iterator<const int*> >();
108 
109 #if TEST_STD_VER >= 20
110     static_assert(test<forward_iterator<const int*>, forward_iterator<const int*>>());
111     static_assert(test<forward_iterator<const int*>, bidirectional_iterator<const int*>>());
112     static_assert(test<forward_iterator<const int*>, random_access_iterator<const int*>>());
113     static_assert(test<bidirectional_iterator<const int*>, forward_iterator<const int*>>());
114     static_assert(test<bidirectional_iterator<const int*>, bidirectional_iterator<const int*>>());
115     static_assert(test<bidirectional_iterator<const int*>, random_access_iterator<const int*>>());
116     static_assert(test<random_access_iterator<const int*>, forward_iterator<const int*>>());
117     static_assert(test<random_access_iterator<const int*>, bidirectional_iterator<const int*>>());
118     static_assert(test<random_access_iterator<const int*>, random_access_iterator<const int*>>());
119 #endif
120 
121     return 0;
122 }
123