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// <numeric>
10
11// Became constexpr in C++20
12// template <InputIterator InIter,
13// OutputIterator<auto, const InIter::value_type&> OutIter>
14// requires HasMinus<InIter::value_type, InIter::value_type>
15// && Constructible<InIter::value_type, InIter::reference>
16// && OutputIterator<OutIter,
17// HasMinus<InIter::value_type, InIter::value_type>::result_type>
18// && MoveAssignable<InIter::value_type>
19// OutIter
20// adjacent_difference(InIter first, InIter last, OutIter result);
21
22#include <numeric>
23#include <cassert>
24
25#include "test_macros.h"
26#include "test_iterators.h"
27
28template <class InIter, class OutIter>
29TEST_CONSTEXPR_CXX20 void
30test()
31{
32 int ia[] = {15, 10, 6, 3, 1};
33 int ir[] = {15, -5, -4, -3, -2};
34 const unsigned s = sizeof(ia) / sizeof(ia[0]);
35 int ib[s] = {0};
36 OutIter r = std::adjacent_difference(InIter(ia), InIter(ia+s), OutIter(ib));
37 assert(base(r) == ib + s);
38 for (unsigned i = 0; i < s; ++i)
39 assert(ib[i] == ir[i]);
40}
41
42#if TEST_STD_VER >= 11
43
44class Y;
45
46class X
47{
48 int i_;
49
50 TEST_CONSTEXPR_CXX20 X& operator=(const X&);
51public:
52 TEST_CONSTEXPR_CXX20 explicit X(int i) : i_(i) {}
53 TEST_CONSTEXPR_CXX20 X(const X& x) : i_(x.i_) {}
54 TEST_CONSTEXPR_CXX20 X& operator=(X&& x)
55 {
56 i_ = x.i_;
57 x.i_ = -1;
58 return *this;
59 }
60
61 TEST_CONSTEXPR_CXX20 friend X operator-(const X& x, const X& y) {return X(x.i_ - y.i_);}
62
63 friend class Y;
64};
65
66class Y
67{
68 int i_;
69
70 TEST_CONSTEXPR_CXX20 Y& operator=(const Y&);
71public:
72 TEST_CONSTEXPR_CXX20 explicit Y(int i) : i_(i) {}
73 TEST_CONSTEXPR_CXX20 Y(const Y& y) : i_(y.i_) {}
74 TEST_CONSTEXPR_CXX20 void operator=(const X& x) {i_ = x.i_;}
75};
76
77#endif
78
79TEST_CONSTEXPR_CXX20 bool
80test()
81{
82 test<cpp17_input_iterator<const int*>, cpp17_output_iterator<int*> >();
83 test<cpp17_input_iterator<const int*>, forward_iterator<int*> >();
84 test<cpp17_input_iterator<const int*>, bidirectional_iterator<int*> >();
85 test<cpp17_input_iterator<const int*>, random_access_iterator<int*> >();
86 test<cpp17_input_iterator<const int*>, int*>();
87
88 test<forward_iterator<const int*>, cpp17_output_iterator<int*> >();
89 test<forward_iterator<const int*>, forward_iterator<int*> >();
90 test<forward_iterator<const int*>, bidirectional_iterator<int*> >();
91 test<forward_iterator<const int*>, random_access_iterator<int*> >();
92 test<forward_iterator<const int*>, int*>();
93
94 test<bidirectional_iterator<const int*>, cpp17_output_iterator<int*> >();
95 test<bidirectional_iterator<const int*>, forward_iterator<int*> >();
96 test<bidirectional_iterator<const int*>, bidirectional_iterator<int*> >();
97 test<bidirectional_iterator<const int*>, random_access_iterator<int*> >();
98 test<bidirectional_iterator<const int*>, int*>();
99
100 test<random_access_iterator<const int*>, cpp17_output_iterator<int*> >();
101 test<random_access_iterator<const int*>, forward_iterator<int*> >();
102 test<random_access_iterator<const int*>, bidirectional_iterator<int*> >();
103 test<random_access_iterator<const int*>, random_access_iterator<int*> >();
104 test<random_access_iterator<const int*>, int*>();
105
106 test<const int*, cpp17_output_iterator<int*> >();
107 test<const int*, forward_iterator<int*> >();
108 test<const int*, bidirectional_iterator<int*> >();
109 test<const int*, random_access_iterator<int*> >();
110 test<const int*, int*>();
111
112#if TEST_STD_VER >= 11
113 X x[3] = {X(1), X(2), X(3)};
114 Y y[3] = {Y(1), Y(2), Y(3)};
115 std::adjacent_difference(x, x+3, y);
116#endif
117
118 return true;
119}
120
121int main(int, char**)
122{
123 test();
124#if TEST_STD_VER > 17
125 static_assert(test());
126#endif
127 return 0;
128}
129

source code of libcxx/test/std/numerics/numeric.ops/adjacent.difference/adjacent_difference.pass.cpp