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 // template<InputIterator Iter1, InputIterator Iter2>
12 //   requires HasLess<Iter1::value_type, Iter2::value_type>
13 //         && HasLess<Iter2::value_type, Iter1::value_type>
14 //   constexpr bool             // constexpr after C++17
15 //   lexicographical_compare(Iter1 first1, Iter1 last1, Iter2 first2, Iter2 last2);
16 
17 #include <algorithm>
18 #include <cassert>
19 
20 #include "test_macros.h"
21 #include "test_iterators.h"
22 
23 #if TEST_STD_VER > 17
test_constexpr()24 TEST_CONSTEXPR bool test_constexpr() {
25     int ia[] = {1, 2, 3};
26     int ib[] = {1, 3, 5, 2, 4, 6};
27 
28     return  std::lexicographical_compare(std::begin(ia), std::end(ia), std::begin(ib), std::end(ib))
29         && !std::lexicographical_compare(std::begin(ib), std::end(ib), std::begin(ia), std::end(ia))
30            ;
31     }
32 #endif
33 
34 template <class Iter1, class Iter2>
35 void
test()36 test()
37 {
38     int ia[] = {1, 2, 3, 4};
39     const unsigned sa = sizeof(ia)/sizeof(ia[0]);
40     int ib[] = {1, 2, 3};
41     assert(!std::lexicographical_compare(Iter1(ia),   Iter1(ia+sa), Iter2(ib),   Iter2(ib+2)));
42     assert( std::lexicographical_compare(Iter1(ib),   Iter1(ib+2),  Iter2(ia),   Iter2(ia+sa)));
43     assert(!std::lexicographical_compare(Iter1(ia),   Iter1(ia+sa), Iter2(ib),   Iter2(ib+3)));
44     assert( std::lexicographical_compare(Iter1(ib),   Iter1(ib+3),  Iter2(ia),   Iter2(ia+sa)));
45     assert( std::lexicographical_compare(Iter1(ia),   Iter1(ia+sa), Iter2(ib+1), Iter2(ib+3)));
46     assert(!std::lexicographical_compare(Iter1(ib+1), Iter1(ib+3),  Iter2(ia),   Iter2(ia+sa)));
47 }
48 
main(int,char **)49 int main(int, char**)
50 {
51     test<cpp17_input_iterator<const int*>, cpp17_input_iterator<const int*> >();
52     test<cpp17_input_iterator<const int*>, forward_iterator<const int*> >();
53     test<cpp17_input_iterator<const int*>, bidirectional_iterator<const int*> >();
54     test<cpp17_input_iterator<const int*>, random_access_iterator<const int*> >();
55     test<cpp17_input_iterator<const int*>, const int*>();
56 
57     test<forward_iterator<const int*>, cpp17_input_iterator<const int*> >();
58     test<forward_iterator<const int*>, forward_iterator<const int*> >();
59     test<forward_iterator<const int*>, bidirectional_iterator<const int*> >();
60     test<forward_iterator<const int*>, random_access_iterator<const int*> >();
61     test<forward_iterator<const int*>, const int*>();
62 
63     test<bidirectional_iterator<const int*>, cpp17_input_iterator<const int*> >();
64     test<bidirectional_iterator<const int*>, forward_iterator<const int*> >();
65     test<bidirectional_iterator<const int*>, bidirectional_iterator<const int*> >();
66     test<bidirectional_iterator<const int*>, random_access_iterator<const int*> >();
67     test<bidirectional_iterator<const int*>, const int*>();
68 
69     test<random_access_iterator<const int*>, cpp17_input_iterator<const int*> >();
70     test<random_access_iterator<const int*>, forward_iterator<const int*> >();
71     test<random_access_iterator<const int*>, bidirectional_iterator<const int*> >();
72     test<random_access_iterator<const int*>, random_access_iterator<const int*> >();
73     test<random_access_iterator<const int*>, const int*>();
74 
75     test<const int*, cpp17_input_iterator<const int*> >();
76     test<const int*, forward_iterator<const int*> >();
77     test<const int*, bidirectional_iterator<const int*> >();
78     test<const int*, random_access_iterator<const int*> >();
79     test<const int*, const int*>();
80 
81 #if TEST_STD_VER > 17
82     static_assert(test_constexpr());
83 #endif
84 
85   return 0;
86 }
87