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 // XFAIL: LIBCXX-WINDOWS-FIXME
14 
15 // default searcher
16 // template<class _ForwardIterator, class _BinaryPredicate = equal_to<>>
17 // class default_searcher {
18 // public:
19 //     default_searcher(_ForwardIterator __f, _ForwardIterator __l,
20 //                             _BinaryPredicate __p = _BinaryPredicate())
21 //         : __first_(__f), __last_(__l), __pred_(__p) {}
22 //
23 //     template <typename _ForwardIterator2>
24 //     pair<_ForwardIterator2, _ForwardIterator2>
25 //     operator () (_ForwardIterator2 __f, _ForwardIterator2 __l) const {
26 //         return std::search(__f, __l, __first_, __last_, __pred_);
27 //         }
28 //
29 // private:
30 //     _ForwardIterator __first_;
31 //     _ForwardIterator __last_;
32 //     _BinaryPredicate __pred_;
33 //     };
34 
35 
36 #include <algorithm>
37 #include <functional>
38 #include <cassert>
39 
40 #include "test_macros.h"
41 #include "test_iterators.h"
42 
43 struct count_equal
44 {
45     int *count;
46 
47     template <class T>
48     TEST_CONSTEXPR_CXX14 bool operator()(const T& x, const T& y) const
49         {++*count; return x == y;}
50 };
51 
52 template <typename Iter1, typename Iter2>
53 TEST_CONSTEXPR_CXX20
54 void do_search(Iter1 b1, Iter1 e1, Iter2 b2, Iter2 e2, Iter1 result) {
55     int count = 0;
56     std::default_searcher<Iter2, count_equal> s{b2, e2, count_equal{&count}};
57     assert(result == std::search(b1, e1, s));
58     auto d1 = std::distance(b1, e1);
59     auto d2 = std::distance(b2, e2);
60     assert((count >= 1) || (d2 == 0) || (d1 < d2));
61     assert((d1 < d2) || count <= d1 * (d1 - d2 + 1));
62 }
63 
64 template <class Iter1, class Iter2>
65 TEST_CONSTEXPR_CXX20
66 bool test()
67 {
68     int ia[] = {0, 1, 2, 3, 4, 5};
69     const unsigned sa = sizeof(ia)/sizeof(ia[0]);
70     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia),      Iter2(ia),    Iter1(ia));
71     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia),      Iter2(ia+1),  Iter1(ia));
72     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia+1),    Iter2(ia+2),  Iter1(ia+1));
73     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia+2),    Iter2(ia+2),  Iter1(ia));
74     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia+2),    Iter2(ia+3),  Iter1(ia+2));
75     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia+2),    Iter2(ia+3),  Iter1(ia+2));
76     do_search(Iter1(ia), Iter1(ia),      Iter2(ia+2),    Iter2(ia+3),  Iter1(ia));
77     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia+sa-1), Iter2(ia+sa), Iter1(ia+sa-1));
78     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia+sa-3), Iter2(ia+sa), Iter1(ia+sa-3));
79     do_search(Iter1(ia), Iter1(ia+sa),   Iter2(ia),      Iter2(ia+sa), Iter1(ia));
80     do_search(Iter1(ia), Iter1(ia+sa-1), Iter2(ia),      Iter2(ia+sa), Iter1(ia+sa-1));
81     do_search(Iter1(ia), Iter1(ia+1),    Iter2(ia),      Iter2(ia+sa), Iter1(ia+1));
82     int ib[] = {0, 1, 2, 0, 1, 2, 3, 0, 1, 2, 3, 4};
83     const unsigned sb = sizeof(ib)/sizeof(ib[0]);
84     int ic[] = {1};
85     do_search(Iter1(ib), Iter1(ib+sb), Iter2(ic), Iter2(ic+1), Iter1(ib+1));
86     int id[] = {1, 2};
87     do_search(Iter1(ib), Iter1(ib+sb), Iter2(id), Iter2(id+2), Iter1(ib+1));
88     int ie[] = {1, 2, 3};
89     do_search(Iter1(ib), Iter1(ib+sb), Iter2(ie), Iter2(ie+3), Iter1(ib+4));
90     int ig[] = {1, 2, 3, 4};
91     do_search(Iter1(ib), Iter1(ib+sb), Iter2(ig), Iter2(ig+4), Iter1(ib+8));
92     int ih[] = {0, 1, 1, 1, 1, 2, 3, 0, 1, 2, 3, 4};
93     const unsigned sh = sizeof(ih)/sizeof(ih[0]);
94     int ii[] = {1, 1, 2};
95     do_search(Iter1(ih), Iter1(ih+sh), Iter2(ii), Iter2(ii+3), Iter1(ih+3));
96 
97     return true;
98 }
99 
100 int main(int, char**) {
101     test<forward_iterator<const int*>, forward_iterator<const int*> >();
102     test<forward_iterator<const int*>, bidirectional_iterator<const int*> >();
103     test<forward_iterator<const int*>, random_access_iterator<const int*> >();
104     test<bidirectional_iterator<const int*>, forward_iterator<const int*> >();
105     test<bidirectional_iterator<const int*>, bidirectional_iterator<const int*> >();
106     test<bidirectional_iterator<const int*>, random_access_iterator<const int*> >();
107     test<random_access_iterator<const int*>, forward_iterator<const int*> >();
108     test<random_access_iterator<const int*>, bidirectional_iterator<const int*> >();
109     test<random_access_iterator<const int*>, random_access_iterator<const int*> >();
110 
111 #if TEST_STD_VER >= 20
112     static_assert(test<forward_iterator<const int*>, forward_iterator<const int*>>());
113     static_assert(test<forward_iterator<const int*>, bidirectional_iterator<const int*>>());
114     static_assert(test<forward_iterator<const int*>, random_access_iterator<const int*>>());
115     static_assert(test<bidirectional_iterator<const int*>, forward_iterator<const int*>>());
116     static_assert(test<bidirectional_iterator<const int*>, bidirectional_iterator<const int*>>());
117     static_assert(test<bidirectional_iterator<const int*>, random_access_iterator<const int*>>());
118     static_assert(test<random_access_iterator<const int*>, forward_iterator<const int*>>());
119     static_assert(test<random_access_iterator<const int*>, bidirectional_iterator<const int*>>());
120     static_assert(test<random_access_iterator<const int*>, random_access_iterator<const int*>>());
121 #endif
122 
123     return 0;
124 }
125