xref: /llvm-project/libcxx/test/std/algorithms/alg.sorting/alg.merge/merge.pass.cpp (revision 5e97d37b960840cabf32dfef3503b28ba5d21dc2)
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 InIter1, InputIterator InIter2, typename OutIter>
12 //   requires OutputIterator<OutIter, InIter1::reference>
13 //         && OutputIterator<OutIter, InIter2::reference>
14 //         && HasLess<InIter2::value_type, InIter1::value_type>
15 //         && HasLess<InIter1::value_type, InIter2::value_type>
16 //   constexpr OutIter       // constexpr after C++17
17 //   merge(InIter1 first1, InIter1 last1, InIter2 first2, InIter2 last2,
18 //         OutIter result);
19 
20 #include <algorithm>
21 #include <cassert>
22 
23 #include "test_macros.h"
24 #include "test_iterators.h"
25 #include "../sortable_helpers.h"
26 
27 template<class T, class Iter1, class Iter2, class OutIter>
test4()28 TEST_CONSTEXPR_CXX20 void test4()
29 {
30     const T a[] = {11, 33, 31, 41};
31     const T b[] = {22, 32, 43, 42, 52};
32     {
33         T result[20] = {};
34         T expected[] = {11, 22, 33, 31, 32, 41, 43, 42, 52};
35         OutIter end = std::merge(Iter1(a), Iter1(a+4), Iter2(b), Iter2(b+5), OutIter(result));
36         assert(std::lexicographical_compare(result, base(end), expected, expected+9, T::less) == 0);
37         for (const T *it = base(end); it != result+20; ++it) {
38             assert(it->value == 0);
39         }
40     }
41     {
42         T result[20] = {};
43         T expected[] = {11, 22, 32, 33, 31, 43, 42, 41, 52};
44         OutIter end = std::merge(Iter1(b), Iter1(b+5), Iter2(a), Iter2(a+4), OutIter(result));
45         assert(std::lexicographical_compare(result, base(end), expected, expected+9, T::less) == 0);
46         for (const T *it = base(end); it != result+20; ++it) {
47             assert(it->value == 0);
48         }
49     }
50 }
51 
52 template<class T, class Iter1, class Iter2>
test3()53 TEST_CONSTEXPR_CXX20 void test3()
54 {
55     test4<T, Iter1, Iter2, cpp17_output_iterator<T*> >();
56     test4<T, Iter1, Iter2, forward_iterator<T*> >();
57     test4<T, Iter1, Iter2, bidirectional_iterator<T*> >();
58     test4<T, Iter1, Iter2, random_access_iterator<T*> >();
59     test4<T, Iter1, Iter2, T*>();
60 }
61 
62 template<class T, class Iter1>
test2()63 TEST_CONSTEXPR_CXX20 void test2()
64 {
65     test3<T, Iter1, cpp17_input_iterator<const T*> >();
66     test3<T, Iter1, forward_iterator<const T*> >();
67     test3<T, Iter1, bidirectional_iterator<const T*> >();
68     test3<T, Iter1, random_access_iterator<const T*> >();
69     test3<T, Iter1, const T*>();
70 }
71 
72 template<class T>
test1()73 TEST_CONSTEXPR_CXX20 void test1()
74 {
75     test2<T, cpp17_input_iterator<const T*> >();
76     test2<T, forward_iterator<const T*> >();
77     test2<T, bidirectional_iterator<const T*> >();
78     test2<T, random_access_iterator<const T*> >();
79     test2<T, const T*>();
80 }
81 
test()82 TEST_CONSTEXPR_CXX20 bool test()
83 {
84     test1<TrivialSortable>();
85     test1<NonTrivialSortable>();
86     return true;
87 }
88 
main(int,char **)89 int main(int, char**)
90 {
91     test();
92 #if TEST_STD_VER > 17
93     static_assert(test());
94 #endif
95 
96     return 0;
97 }
98