1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
|
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
// <ranges>
// std::views::chunk_by
#include <ranges>
#include <algorithm>
#include <cassert>
#include <concepts>
#include <initializer_list>
#include <type_traits>
#include <utility>
#include "test_iterators.h"
#include "test_range.h"
struct Pred {
constexpr bool operator()(int x, int y) const { return x != -y; }
};
struct NonCopyablePredicate : Pred {
NonCopyablePredicate(NonCopyablePredicate const&) = delete;
};
struct Range : std::ranges::view_base {
using Iterator = forward_iterator<int*>;
using Sentinel = sentinel_wrapper<Iterator>;
constexpr explicit Range(int* b, int* e) : begin_(b), end_(e) {}
constexpr Iterator begin() const { return Iterator(begin_); }
constexpr Sentinel end() const { return Sentinel(Iterator(end_)); }
private:
int* begin_;
int* end_;
};
template <typename View>
constexpr void compareViews(View v, std::initializer_list<std::initializer_list<int>> list) {
auto b1 = v.begin();
auto e1 = v.end();
auto b2 = list.begin();
auto e2 = list.end();
for (; b1 != e1 && b2 != e2; ++b1, ++b2) {
bool eq = std::ranges::equal(*b1, *b2, [](int x, int y) {
assert(x == y);
return true;
});
assert(eq);
}
assert(b1 == e1);
assert(b2 == e2);
}
constexpr int absoluteValue(int x) { return x < 0 ? -x : x; }
template <class T>
constexpr const T&& asConstRvalue(T&& t) {
return static_cast<T const&&>(t);
}
constexpr bool test() {
int buff[] = {-4, -3, -2, -1, 1, 2, 3, 4};
// Test range adaptor object
{
using RangeAdaptorObject = decltype(std::views::chunk_by);
static_assert(std::is_const_v<RangeAdaptorObject>);
// The type of a customization point object, ignoring cv-qualifiers, shall model semiregular
static_assert(std::semiregular<std::remove_const<RangeAdaptorObject>>);
}
// Test `views::chunk_by(pred)(v)`
{
using Result = std::ranges::chunk_by_view<Range, Pred>;
Range const range(buff, buff + 8);
Pred pred;
{
// 'views::chunk_by(pred)' - &&
std::same_as<Result> decltype(auto) result = std::views::chunk_by(pred)(range);
compareViews(result, {{-4, -3, -2, -1}, {1, 2, 3, 4}});
}
{
// 'views::chunk_by(pred)' - const&&
std::same_as<Result> decltype(auto) result = asConstRvalue(std::views::chunk_by(pred))(range);
compareViews(result, {{-4, -3, -2, -1}, {1, 2, 3, 4}});
}
{
// 'views::chunk_by(pred)' - &
auto partial = std::views::chunk_by(pred);
std::same_as<Result> decltype(auto) result = partial(range);
compareViews(result, {{-4, -3, -2, -1}, {1, 2, 3, 4}});
}
{
// 'views::chunk_by(pred)' - const&
auto const partial = std::views::chunk_by(pred);
std::same_as<Result> decltype(auto) result = partial(range);
compareViews(result, {{-4, -3, -2, -1}, {1, 2, 3, 4}});
}
}
// Test `v | views::chunk_by(pred)`
{
using Result = std::ranges::chunk_by_view<Range, Pred>;
Range const range(buff, buff + 8);
Pred pred;
{
// 'views::chunk_by(pred)' - &&
std::same_as<Result> decltype(auto) result = range | std::views::chunk_by(pred);
compareViews(result, {{-4, -3, -2, -1}, {1, 2, 3, 4}});
}
{
// 'views::chunk_by(pred)' - const&&
std::same_as<Result> decltype(auto) result = range | asConstRvalue(std::views::chunk_by(pred));
compareViews(result, {{-4, -3, -2, -1}, {1, 2, 3, 4}});
}
{
// 'views::chunk_by(pred)' - &
auto partial = std::views::chunk_by(pred);
std::same_as<Result> decltype(auto) result = range | partial;
compareViews(result, {{-4, -3, -2, -1}, {1, 2, 3, 4}});
}
{
// 'views::chunk_by(pred)' - const&
auto const partial = std::views::chunk_by(pred);
std::same_as<Result> decltype(auto) result = range | partial;
compareViews(result, {{-4, -3, -2, -1}, {1, 2, 3, 4}});
}
}
// Test `views::chunk_by(v, pred)` range adaptor object
{
using Result = std::ranges::chunk_by_view<Range, Pred>;
Range const range(buff, buff + 8);
Pred pred;
{
// 'views::chunk_by' - &&
auto range_adaptor = std::views::chunk_by;
std::same_as<Result> decltype(auto) result = std::move(range_adaptor)(range, pred);
compareViews(result, {{-4, -3, -2, -1}, {1, 2, 3, 4}});
}
{
// 'views::chunk_by' - const&&
auto const range_adaptor = std::views::chunk_by;
std::same_as<Result> decltype(auto) result = std::move(range_adaptor)(range, pred);
compareViews(result, {{-4, -3, -2, -1}, {1, 2, 3, 4}});
}
{
// 'views::chunk_by' - &
auto range_adaptor = std::views::chunk_by;
std::same_as<Result> decltype(auto) result = range_adaptor(range, pred);
compareViews(result, {{-4, -3, -2, -1}, {1, 2, 3, 4}});
}
{
// 'views::chunk_by' - const&
auto const range_adaptor = std::views::chunk_by;
std::same_as<Result> decltype(auto) result = range_adaptor(range, pred);
compareViews(result, {{-4, -3, -2, -1}, {1, 2, 3, 4}});
}
}
// Test that one can call std::views::chunk_by with arbitrary stuff, as long as we
// don't try to actually complete the call by passing it a range.
//
// That makes no sense and we can't do anything with the result, but it's valid.
{
int array[3] = {1, 2, 3};
[[maybe_unused]] auto partial = std::views::chunk_by(std::move(array));
}
// Test `adaptor | views::chunk_by(pred)`
{
Range const range(buff, buff + 8);
{
auto pred1 = [](int i) { return absoluteValue(i) < 3; };
Pred pred2;
using Result = std::ranges::chunk_by_view<std::ranges::filter_view<Range, decltype(pred1)>, Pred>;
std::same_as<Result> decltype(auto) result = range | std::views::filter(pred1) | std::views::chunk_by(pred2);
compareViews(result, {{-2, -1}, {1, 2}});
}
{
auto pred1 = [](int i) { return absoluteValue(i) < 3; };
Pred pred2;
using Result = std::ranges::chunk_by_view<std::ranges::filter_view<Range, decltype(pred1)>, Pred>;
auto const partial = std::views::filter(pred1) | std::views::chunk_by(pred2);
std::same_as<Result> decltype(auto) result = range | partial;
compareViews(result, {{-2, -1}, {1, 2}});
}
}
// Test SFINAE friendliness
{
struct NotAView {};
struct NotInvocable {};
static_assert(!CanBePiped<Range, decltype(std::views::chunk_by)>);
static_assert(CanBePiped<Range, decltype(std::views::chunk_by(Pred{}))>);
static_assert(!CanBePiped<NotAView, decltype(std::views::chunk_by(Pred{}))>);
static_assert(!CanBePiped<std::initializer_list<int>, decltype(std::views::chunk_by(Pred{}))>);
static_assert(!CanBePiped<Range, decltype(std::views::chunk_by(NotInvocable{}))>);
static_assert(!std::is_invocable_v<decltype(std::views::chunk_by)>);
static_assert(!std::is_invocable_v<decltype(std::views::chunk_by), Pred, Range>);
static_assert(std::is_invocable_v<decltype(std::views::chunk_by), Range, Pred>);
static_assert(!std::is_invocable_v<decltype(std::views::chunk_by), Range, Pred, Pred>);
static_assert(!std::is_invocable_v<decltype(std::views::chunk_by), NonCopyablePredicate>);
}
{ static_assert(std::is_same_v<decltype(std::ranges::views::chunk_by), decltype(std::views::chunk_by)>); }
return true;
}
int main(int, char**) {
test();
static_assert(test());
return 0;
}
|
