xref: /llvm-project/libcxx/test/std/algorithms/alg.modifying.operations/alg.fill/fill.pass.cpp (revision e99c4906e44ae3f921fa05356909d006cda8d954)
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 // template<ForwardIterator Iter, class T>
12 //   requires OutputIterator<Iter, const T&>
13 //   constexpr void      // constexpr after C++17
14 //   fill(Iter first, Iter last, const T& value);
15 
16 #include <algorithm>
17 #include <array>
18 #include <cassert>
19 #include <cstddef>
20 #include <vector>
21 
22 #include "test_macros.h"
23 #include "test_iterators.h"
24 
25 template <class Iter, class Container>
26 TEST_CONSTEXPR_CXX20 void
27 test(Container in, size_t from, size_t to, typename Container::value_type value, Container expected) {
28   std::fill(Iter(in.data() + from), Iter(in.data() + to), value);
29   assert(in == expected);
30 }
31 
32 template <class T>
33 struct Test {
34   template <class Iter>
35   TEST_CONSTEXPR_CXX20 void operator()() {
36     {
37       std::array<T, 4> in       = {1, 2, 3, 4};
38       std::array<T, 4> expected = {5, 5, 5, 5};
39       test<Iter>(in, 0, 4, 5, expected);
40     }
41     {
42       std::array<T, 4> in       = {1, 2, 3, 4};
43       std::array<T, 4> expected = {1, 5, 5, 4};
44       test<Iter>(in, 1, 3, 5, expected);
45     }
46   }
47 };
48 
49 TEST_CONSTEXPR_CXX20 bool test() {
50   types::for_each(types::forward_iterator_list<char*>(), Test<char>());
51   types::for_each(types::forward_iterator_list<int*>(), Test<int>());
52   {   // test vector<bool>::iterator optimization
53     { // simple case
54       std::vector<bool> in(4, false);
55       std::vector<bool> expected(4, true);
56       std::fill(in.begin(), in.end(), true);
57       assert(in == expected);
58     }
59     { // partial byte in the front is not filled
60       std::vector<bool> in(8, false);
61       std::vector<bool> expected(8, true);
62       expected[0] = false;
63       expected[1] = false;
64       std::fill(in.begin() + 2, in.end(), true);
65       assert(in == expected);
66     }
67     { // partial byte in the back is not filled
68       std::vector<bool> in(8, false);
69       std::vector<bool> expected(8, true);
70       expected[6] = false;
71       expected[7] = false;
72       std::fill(in.begin(), in.end() - 2, true);
73       assert(in == expected);
74     }
75     { // partial byte in the front and back is not filled
76       std::vector<bool> in(16, false);
77       std::vector<bool> expected(16, true);
78       expected[0]  = false;
79       expected[1]  = false;
80       expected[14] = false;
81       expected[15] = false;
82       std::fill(in.begin() + 2, in.end() - 2, true);
83       assert(in == expected);
84     }
85     { // only a few bits of a byte are set
86       std::vector<bool> in(8, false);
87       std::vector<bool> expected(8, true);
88       expected[0] = false;
89       expected[1] = false;
90       expected[6] = false;
91       expected[7] = false;
92       std::fill(in.begin() + 2, in.end() - 2, true);
93       assert(in == expected);
94     }
95   }
96   return true;
97 }
98 
99 int main(int, char**) {
100   test();
101 #if TEST_STD_VER >= 20
102   static_assert(test());
103 #endif
104 
105   return 0;
106 }
107