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// UNSUPPORTED: c++03, c++11, c++14, c++17
12
13// template<class T, output_iterator<const T&> O, sentinel_for<O> S>
14// constexpr O ranges::fill(O first, S last, const T& value);
15// template<class T, output_range<const T&> R>
16// constexpr borrowed_iterator_t<R> ranges::fill(R&& r, const T& value);
17
18#include <algorithm>
19#include <array>
20#include <cassert>
21#include <ranges>
22#include <string>
23#include <vector>
24
25#include "sized_allocator.h"
26#include "almost_satisfies_types.h"
27#include "test_iterators.h"
28#include "test_macros.h"
29
30template <class Iter, class Sent = sentinel_wrapper<Iter>>
31concept HasFillIt = requires(Iter iter, Sent sent) { std::ranges::fill(iter, sent, int{}); };
32
33static_assert(HasFillIt<int*>);
34static_assert(!HasFillIt<OutputIteratorNotIndirectlyWritable>);
35static_assert(!HasFillIt<OutputIteratorNotInputOrOutputIterator>);
36static_assert(!HasFillIt<int*, SentinelForNotSemiregular>);
37static_assert(!HasFillIt<int*, SentinelForNotWeaklyEqualityComparableWith>);
38
39template <class Range>
40concept HasFillR = requires(Range range) { std::ranges::fill(range, int{}); };
41
42static_assert(HasFillR<UncheckedRange<int*>>);
43static_assert(!HasFillR<OutputRangeNotIndirectlyWritable>);
44static_assert(!HasFillR<OutputRangeNotInputOrOutputIterator>);
45static_assert(!HasFillR<OutputRangeNotSentinelSemiregular>);
46static_assert(!HasFillR<OutputRangeNotSentinelEqualityComparableWith>);
47
48template <class It, class Sent = It>
49constexpr void test_iterators() {
50 { // simple test
51 {
52 int a[3];
53 std::same_as<It> auto ret = std::ranges::fill(It(a), Sent(It(a + 3)), 1);
54 assert(std::all_of(a, a + 3, [](int i) { return i == 1; }));
55 assert(base(ret) == a + 3);
56 }
57 {
58 int a[3];
59 auto range = std::ranges::subrange(It(a), Sent(It(a + 3)));
60 std::same_as<It> auto ret = std::ranges::fill(range, 1);
61 assert(std::all_of(a, a + 3, [](int i) { return i == 1; }));
62 assert(base(ret) == a + 3);
63 }
64 }
65
66 { // check that an empty range works
67 {
68 std::array<int, 0> a;
69 auto ret = std::ranges::fill(It(a.data()), Sent(It(a.data())), 1);
70 assert(base(ret) == a.data());
71 }
72 {
73 std::array<int, 0> a;
74 auto range = std::ranges::subrange(It(a.data()), Sent(It(a.data())));
75 auto ret = std::ranges::fill(range, 1);
76 assert(base(ret) == a.data());
77 }
78 }
79}
80
81// The `ranges::{fill, fill_n}` algorithms require `vector<bool, Alloc>::iterator` to satisfy
82// the `std::indirectly_writable` concept when used with `vector<bool, Alloc>`, which is only
83// satisfied since C++23.
84#if TEST_STD_VER >= 23
85constexpr bool test_vector_bool(std::size_t N) {
86 { // Test cases validating leading/trailing bits unfilled remain unchanged
87 { // Leading bits are not filled
88 std::vector<bool> in(N, false);
89 std::vector<bool> expected(N, true);
90 expected[0] = expected[1] = false;
91 std::ranges::fill(std::ranges::subrange(in.begin() + 2, in.end()), true);
92 assert(in == expected);
93 }
94 { // Trailing bits are not filled
95 std::vector<bool> in(N, false);
96 std::vector<bool> expected(N, true);
97 expected[N - 1] = expected[N - 2] = false;
98 std::ranges::fill(std::ranges::subrange(in.begin(), in.end() - 2), true);
99 assert(in == expected);
100 }
101 { // Leading and trailing bits are not filled
102 std::vector<bool> in(N, false);
103 std::vector<bool> expected(N, true);
104 expected[0] = expected[1] = expected[N - 1] = expected[N - 2] = false;
105 std::ranges::fill(std::ranges::subrange(in.begin() + 2, in.end() - 2), true);
106 assert(in == expected);
107 }
108 }
109
110 { // Test cases with full or partial bytes filled
111 { // Full bytes filled
112 std::vector<bool> in(N, false);
113 std::vector<bool> expected(N, true);
114 std::ranges::fill(in, true);
115 assert(in == expected);
116 }
117 { // Partial bytes with offset filled
118 std::vector<bool> in(N, false);
119 std::vector<bool> expected(N, true);
120 std::ranges::fill(std::ranges::subrange(std::ranges::begin(in) + 4, std::ranges::end(in) - 4), true);
121 std::ranges::fill(std::ranges::subrange(std::ranges::begin(expected), std::ranges::begin(expected) + 4), false);
122 std::ranges::fill(std::ranges::subrange(std::ranges::end(expected) - 4, std::ranges::end(expected)), false);
123 assert(in == expected);
124 }
125 }
126
127 return true;
128}
129#endif
130
131constexpr bool test() {
132 test_iterators<cpp17_output_iterator<int*>, sentinel_wrapper<cpp17_output_iterator<int*>>>();
133 test_iterators<cpp20_output_iterator<int*>, sentinel_wrapper<cpp20_output_iterator<int*>>>();
134 test_iterators<forward_iterator<int*>>();
135 test_iterators<bidirectional_iterator<int*>>();
136 test_iterators<random_access_iterator<int*>>();
137 test_iterators<contiguous_iterator<int*>>();
138 test_iterators<int*>();
139
140 { // check that every element is copied once
141 struct S {
142 bool copied = false;
143 constexpr S& operator=(const S&) {
144 copied = true;
145 return *this;
146 }
147 };
148 {
149 S a[5];
150 std::ranges::fill(a, a + 5, S{true});
151 assert(std::all_of(a, a + 5, [](S& s) { return s.copied; }));
152 }
153 {
154 S a[5];
155 std::ranges::fill(a, S{true});
156 assert(std::all_of(a, a + 5, [](S& s) { return s.copied; }));
157 }
158 }
159
160 { // check that std::ranges::dangling is returned
161 [[maybe_unused]] std::same_as<std::ranges::dangling> decltype(auto) ret =
162 std::ranges::fill(std::array<int, 10>{}, 1);
163 }
164
165 { // check that std::ranges::dangling isn't returned with a borrowing range
166 std::array<int, 10> a{};
167 [[maybe_unused]] std::same_as<std::array<int, 10>::iterator> decltype(auto) ret =
168 std::ranges::fill(std::views::all(a), 1);
169 assert(std::all_of(a.begin(), a.end(), [](int i) { return i == 1; }));
170 }
171
172 { // check that non-trivially copyable items are copied properly
173 {
174 std::array<std::string, 10> a;
175 auto ret = std::ranges::fill(a.begin(), a.end(), "long long string so no SSO");
176 assert(ret == a.end());
177 assert(std::all_of(a.begin(), a.end(), [](auto& s) { return s == "long long string so no SSO"; }));
178 }
179 {
180 std::array<std::string, 10> a;
181 auto ret = std::ranges::fill(a, "long long string so no SSO");
182 assert(ret == a.end());
183 assert(std::all_of(a.begin(), a.end(), [](auto& s) { return s == "long long string so no SSO"; }));
184 }
185 }
186
187#if TEST_STD_VER >= 23
188 { // Test vector<bool>::iterator optimization
189 assert(test_vector_bool(8));
190 assert(test_vector_bool(19));
191 assert(test_vector_bool(32));
192 assert(test_vector_bool(49));
193 assert(test_vector_bool(64));
194 assert(test_vector_bool(199));
195 assert(test_vector_bool(256));
196
197 // Make sure std::ranges::fill behaves properly with std::vector<bool> iterators with custom
198 // size types. See https://github.com/llvm/llvm-project/pull/122410.
199 {
200 using Alloc = sized_allocator<bool, std::uint8_t, std::int8_t>;
201 std::vector<bool, Alloc> in(100, false, Alloc(1));
202 std::vector<bool, Alloc> expected(100, true, Alloc(1));
203 std::ranges::fill(in, true);
204 assert(in == expected);
205 }
206 {
207 using Alloc = sized_allocator<bool, std::uint16_t, std::int16_t>;
208 std::vector<bool, Alloc> in(200, false, Alloc(1));
209 std::vector<bool, Alloc> expected(200, true, Alloc(1));
210 std::ranges::fill(in, true);
211 assert(in == expected);
212 }
213 {
214 using Alloc = sized_allocator<bool, std::uint32_t, std::int32_t>;
215 std::vector<bool, Alloc> in(200, false, Alloc(1));
216 std::vector<bool, Alloc> expected(200, true, Alloc(1));
217 std::ranges::fill(in, true);
218 assert(in == expected);
219 }
220 {
221 using Alloc = sized_allocator<bool, std::uint64_t, std::int64_t>;
222 std::vector<bool, Alloc> in(200, false, Alloc(1));
223 std::vector<bool, Alloc> expected(200, true, Alloc(1));
224 std::ranges::fill(in, true);
225 assert(in == expected);
226 }
227 }
228#endif
229
230 return true;
231}
232
233int main(int, char**) {
234 test();
235 static_assert(test());
236
237 return 0;
238}
239

source code of libcxx/test/std/algorithms/alg.modifying.operations/alg.fill/ranges.fill.pass.cpp