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 // UNSUPPORTED: libcpp-has-no-incomplete-ranges
13
14 // template<class T, output_iterator<const T&> O>
15 // constexpr O ranges::fill_n(O first, iter_difference_t<O> n, const T& value);
16
17 #include <algorithm>
18 #include <array>
19 #include <cassert>
20 #include <ranges>
21 #include <string>
22
23 #include "almost_satisfies_types.h"
24 #include "test_iterators.h"
25
26 template <class Iter>
27 concept HasFillN = requires(Iter iter) { std::ranges::fill_n(iter, int{}, int{}); };
28
29 struct WrongType {};
30
31 static_assert(HasFillN<int*>);
32 static_assert(!HasFillN<WrongType*>);
33 static_assert(!HasFillN<OutputIteratorNotIndirectlyWritable>);
34 static_assert(!HasFillN<OutputIteratorNotInputOrOutputIterator>);
35
36 template <class It, class Sent = It>
test_iterators()37 constexpr void test_iterators() {
38 { // simple test
39 int a[3];
40 std::same_as<It> decltype(auto) ret = std::ranges::fill_n(It(a), 3, 1);
41 assert(std::all_of(a, a + 3, [](int i) { return i == 1; }));
42 assert(base(ret) == a + 3);
43 }
44
45 { // check that an empty range works
46 std::array<int, 0> a;
47 auto ret = std::ranges::fill_n(It(a.data()), 0, 1);
48 assert(base(ret) == a.data());
49 }
50 }
51
test()52 constexpr bool test() {
53 test_iterators<cpp17_output_iterator<int*>, sentinel_wrapper<cpp17_output_iterator<int*>>>();
54 test_iterators<cpp20_output_iterator<int*>, sentinel_wrapper<cpp20_output_iterator<int*>>>();
55 test_iterators<forward_iterator<int*>>();
56 test_iterators<bidirectional_iterator<int*>>();
57 test_iterators<random_access_iterator<int*>>();
58 test_iterators<contiguous_iterator<int*>>();
59 test_iterators<int*>();
60
61 { // check that every element is copied once
62 struct S {
63 bool copied = false;
64 constexpr S& operator=(const S&) {
65 assert(!copied);
66 copied = true;
67 return *this;
68 }
69 };
70
71 S a[5];
72 std::ranges::fill_n(a, 5, S {});
73 assert(std::all_of(a, a + 5, [](S& s) { return s.copied; }));
74 }
75
76 { // check that non-trivially copyable items are copied properly
77 std::array<std::string, 10> a;
78 auto ret = std::ranges::fill_n(a.data(), 10, "long long string so no SSO");
79 assert(ret == a.data() + a.size());
80 assert(std::all_of(a.begin(), a.end(), [](auto& s) { return s == "long long string so no SSO"; }));
81 }
82
83 return true;
84 }
85
main(int,char **)86 int main(int, char**) {
87 test();
88 static_assert(test());
89
90 return 0;
91 }
92