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 // Callable<auto, const InIter::value_type&, const InIter::value_type&> BinaryOperation>
15 // requires Constructible<InIter::value_type, InIter::reference>
16 // && OutputIterator<OutIter, BinaryOperation::result_type>
17 // && MoveAssignable<InIter::value_type>
18 // && CopyConstructible<BinaryOperation>
19 // OutIter
20 // adjacent_difference(InIter first, InIter last, OutIter result, BinaryOperation binary_op);
21
22 #include <numeric>
23 #include <functional>
24 #include <string>
25 #include <cassert>
26
27 #include "test_macros.h"
28 #include "test_iterators.h"
29
30 #if TEST_STD_VER > 17
31 struct rvalue_subtractable
32 {
33 bool correctOperatorUsed = false;
34
35 // make sure the predicate is passed an rvalue and an lvalue (so check that the first argument was moved)
operator ()rvalue_subtractable36 constexpr rvalue_subtractable operator()(rvalue_subtractable const&, rvalue_subtractable&& r) {
37 r.correctOperatorUsed = true;
38 return std::move(r);
39 }
40 };
41
operator -(rvalue_subtractable const &,rvalue_subtractable & rhs)42 constexpr rvalue_subtractable operator-(rvalue_subtractable const&, rvalue_subtractable& rhs)
43 {
44 rhs.correctOperatorUsed = false;
45 return rhs;
46 }
47
operator -(rvalue_subtractable const &,rvalue_subtractable && rhs)48 constexpr rvalue_subtractable operator-(rvalue_subtractable const&, rvalue_subtractable&& rhs)
49 {
50 rhs.correctOperatorUsed = true;
51 return std::move(rhs);
52 }
53
54 constexpr void
test_use_move()55 test_use_move()
56 {
57 const std::size_t size = 100;
58 rvalue_subtractable arr[size];
59 rvalue_subtractable res1[size];
60 rvalue_subtractable res2[size];
61 std::adjacent_difference(arr, arr + size, res1);
62 std::adjacent_difference(arr, arr + size, res2, /*predicate=*/rvalue_subtractable());
63 // start at 1 because the first element is not moved
64 for (unsigned i = 1; i < size; ++i) assert(res1[i].correctOperatorUsed);
65 for (unsigned i = 1; i < size; ++i) assert(res2[i].correctOperatorUsed);
66 }
67 #endif // TEST_STD_VER > 17
68
test_string()69 TEST_CONSTEXPR_CXX20 void test_string() {
70 std::string sa[] = {"a", "b", "c"};
71 std::string sr[] = {"a", "ba", "cb"};
72 std::string output[3];
73 std::adjacent_difference(sa, sa + 3, output, std::plus<std::string>());
74 for (unsigned i = 0; i < 3; ++i) assert(output[i] == sr[i]);
75 }
76
77 template <class InIter, class OutIter>
78 TEST_CONSTEXPR_CXX20 void
test()79 test()
80 {
81 int ia[] = {15, 10, 6, 3, 1};
82 int ir[] = {15, 25, 16, 9, 4};
83 const unsigned s = sizeof(ia) / sizeof(ia[0]);
84 int ib[s] = {0};
85 OutIter r = std::adjacent_difference(InIter(ia), InIter(ia+s), OutIter(ib),
86 std::plus<int>());
87 assert(base(r) == ib + s);
88 for (unsigned i = 0; i < s; ++i)
89 assert(ib[i] == ir[i]);
90 }
91
92 #if TEST_STD_VER >= 11
93
94 class Y;
95
96 class X
97 {
98 int i_;
99
100 TEST_CONSTEXPR_CXX20 X& operator=(const X&);
101 public:
X(int i)102 TEST_CONSTEXPR_CXX20 explicit X(int i) : i_(i) {}
X(const X & x)103 TEST_CONSTEXPR_CXX20 X(const X& x) : i_(x.i_) {}
operator =(X && x)104 TEST_CONSTEXPR_CXX20 X& operator=(X&& x)
105 {
106 i_ = x.i_;
107 x.i_ = -1;
108 return *this;
109 }
110
operator -(const X & x,const X & y)111 TEST_CONSTEXPR_CXX20 friend X operator-(const X& x, const X& y) {return X(x.i_ - y.i_);}
112
113 friend class Y;
114 };
115
116 class Y
117 {
118 int i_;
119
120 TEST_CONSTEXPR_CXX20 Y& operator=(const Y&);
121 public:
Y(int i)122 TEST_CONSTEXPR_CXX20 explicit Y(int i) : i_(i) {}
Y(const Y & y)123 TEST_CONSTEXPR_CXX20 Y(const Y& y) : i_(y.i_) {}
operator =(const X & x)124 TEST_CONSTEXPR_CXX20 void operator=(const X& x) {i_ = x.i_;}
125 };
126
127 #endif
128
129
130 TEST_CONSTEXPR_CXX20 bool
test()131 test()
132 {
133 test<cpp17_input_iterator<const int*>, cpp17_output_iterator<int*> >();
134 test<cpp17_input_iterator<const int*>, forward_iterator<int*> >();
135 test<cpp17_input_iterator<const int*>, bidirectional_iterator<int*> >();
136 test<cpp17_input_iterator<const int*>, random_access_iterator<int*> >();
137 test<cpp17_input_iterator<const int*>, int*>();
138
139 test<forward_iterator<const int*>, cpp17_output_iterator<int*> >();
140 test<forward_iterator<const int*>, forward_iterator<int*> >();
141 test<forward_iterator<const int*>, bidirectional_iterator<int*> >();
142 test<forward_iterator<const int*>, random_access_iterator<int*> >();
143 test<forward_iterator<const int*>, int*>();
144
145 test<bidirectional_iterator<const int*>, cpp17_output_iterator<int*> >();
146 test<bidirectional_iterator<const int*>, forward_iterator<int*> >();
147 test<bidirectional_iterator<const int*>, bidirectional_iterator<int*> >();
148 test<bidirectional_iterator<const int*>, random_access_iterator<int*> >();
149 test<bidirectional_iterator<const int*>, int*>();
150
151 test<random_access_iterator<const int*>, cpp17_output_iterator<int*> >();
152 test<random_access_iterator<const int*>, forward_iterator<int*> >();
153 test<random_access_iterator<const int*>, bidirectional_iterator<int*> >();
154 test<random_access_iterator<const int*>, random_access_iterator<int*> >();
155 test<random_access_iterator<const int*>, int*>();
156
157 test<const int*, cpp17_output_iterator<int*> >();
158 test<const int*, forward_iterator<int*> >();
159 test<const int*, bidirectional_iterator<int*> >();
160 test<const int*, random_access_iterator<int*> >();
161 test<const int*, int*>();
162
163 #if TEST_STD_VER >= 11
164 X x[3] = {X(1), X(2), X(3)};
165 Y y[3] = {Y(1), Y(2), Y(3)};
166 std::adjacent_difference(x, x+3, y, std::minus<X>());
167 #endif
168
169 #if TEST_STD_VER > 17
170 test_use_move();
171 #endif // TEST_STD_VER > 17
172
173 test_string();
174
175 return true;
176 }
177
main(int,char **)178 int main(int, char**)
179 {
180 test();
181 #if TEST_STD_VER > 17
182 static_assert(test());
183 #endif
184 return 0;
185 }
186