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
69 // C++20 can use string in constexpr evaluation, but both libc++ and MSVC
70 // don't have the support yet. In these cases omit the constexpr test.
71 // FIXME Remove constexpr string workaround introduced in D90569
72 #if TEST_STD_VER > 17 && \
73 (!defined(__cpp_lib_constexpr_string) || __cpp_lib_constexpr_string < 201907L)
74 void
75 #else
76 TEST_CONSTEXPR_CXX20 void
77 #endif
test_string()78 test_string()
79 {
80 std::string sa[] = {"a", "b", "c"};
81 std::string sr[] = {"a", "ba", "cb"};
82 std::string output[3];
83 std::adjacent_difference(sa, sa + 3, output, std::plus<std::string>());
84 for (unsigned i = 0; i < 3; ++i) assert(output[i] == sr[i]);
85 }
86
87 template <class InIter, class OutIter>
88 TEST_CONSTEXPR_CXX20 void
test()89 test()
90 {
91 int ia[] = {15, 10, 6, 3, 1};
92 int ir[] = {15, 25, 16, 9, 4};
93 const unsigned s = sizeof(ia) / sizeof(ia[0]);
94 int ib[s] = {0};
95 OutIter r = std::adjacent_difference(InIter(ia), InIter(ia+s), OutIter(ib),
96 std::plus<int>());
97 assert(base(r) == ib + s);
98 for (unsigned i = 0; i < s; ++i)
99 assert(ib[i] == ir[i]);
100 }
101
102 #if TEST_STD_VER >= 11
103
104 class Y;
105
106 class X
107 {
108 int i_;
109
110 TEST_CONSTEXPR_CXX20 X& operator=(const X&);
111 public:
X(int i)112 TEST_CONSTEXPR_CXX20 explicit X(int i) : i_(i) {}
X(const X & x)113 TEST_CONSTEXPR_CXX20 X(const X& x) : i_(x.i_) {}
operator =(X && x)114 TEST_CONSTEXPR_CXX20 X& operator=(X&& x)
115 {
116 i_ = x.i_;
117 x.i_ = -1;
118 return *this;
119 }
120
operator -(const X & x,const X & y)121 TEST_CONSTEXPR_CXX20 friend X operator-(const X& x, const X& y) {return X(x.i_ - y.i_);}
122
123 friend class Y;
124 };
125
126 class Y
127 {
128 int i_;
129
130 TEST_CONSTEXPR_CXX20 Y& operator=(const Y&);
131 public:
Y(int i)132 TEST_CONSTEXPR_CXX20 explicit Y(int i) : i_(i) {}
Y(const Y & y)133 TEST_CONSTEXPR_CXX20 Y(const Y& y) : i_(y.i_) {}
operator =(const X & x)134 TEST_CONSTEXPR_CXX20 void operator=(const X& x) {i_ = x.i_;}
135 };
136
137 #endif
138
139
140 TEST_CONSTEXPR_CXX20 bool
test()141 test()
142 {
143 test<cpp17_input_iterator<const int*>, cpp17_output_iterator<int*> >();
144 test<cpp17_input_iterator<const int*>, forward_iterator<int*> >();
145 test<cpp17_input_iterator<const int*>, bidirectional_iterator<int*> >();
146 test<cpp17_input_iterator<const int*>, random_access_iterator<int*> >();
147 test<cpp17_input_iterator<const int*>, int*>();
148
149 test<forward_iterator<const int*>, cpp17_output_iterator<int*> >();
150 test<forward_iterator<const int*>, forward_iterator<int*> >();
151 test<forward_iterator<const int*>, bidirectional_iterator<int*> >();
152 test<forward_iterator<const int*>, random_access_iterator<int*> >();
153 test<forward_iterator<const int*>, int*>();
154
155 test<bidirectional_iterator<const int*>, cpp17_output_iterator<int*> >();
156 test<bidirectional_iterator<const int*>, forward_iterator<int*> >();
157 test<bidirectional_iterator<const int*>, bidirectional_iterator<int*> >();
158 test<bidirectional_iterator<const int*>, random_access_iterator<int*> >();
159 test<bidirectional_iterator<const int*>, int*>();
160
161 test<random_access_iterator<const int*>, cpp17_output_iterator<int*> >();
162 test<random_access_iterator<const int*>, forward_iterator<int*> >();
163 test<random_access_iterator<const int*>, bidirectional_iterator<int*> >();
164 test<random_access_iterator<const int*>, random_access_iterator<int*> >();
165 test<random_access_iterator<const int*>, int*>();
166
167 test<const int*, cpp17_output_iterator<int*> >();
168 test<const int*, forward_iterator<int*> >();
169 test<const int*, bidirectional_iterator<int*> >();
170 test<const int*, random_access_iterator<int*> >();
171 test<const int*, int*>();
172
173 #if TEST_STD_VER >= 11
174 X x[3] = {X(1), X(2), X(3)};
175 Y y[3] = {Y(1), Y(2), Y(3)};
176 std::adjacent_difference(x, x+3, y, std::minus<X>());
177 #endif
178
179 #if TEST_STD_VER > 17
180 test_use_move();
181 #endif // TEST_STD_VER > 17
182 // C++20 can use string in constexpr evaluation, but both libc++ and MSVC
183 // don't have the support yet. In these cases omit the constexpr test.
184 // FIXME Remove constexpr string workaround introduced in D90569
185 #if TEST_STD_VER > 17 && \
186 (!defined(__cpp_lib_constexpr_string) || __cpp_lib_constexpr_string < 201907L)
187 if (!std::is_constant_evaluated())
188 #endif
189 test_string();
190
191 return true;
192 }
193
main(int,char **)194 int main(int, char**)
195 {
196 test();
197 #if TEST_STD_VER > 17
198 static_assert(test());
199 #endif
200 return 0;
201 }
202