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 // UNSUPPORTED: c++03, c++11, c++14
10 // UNSUPPORTED: clang-8
11 // UNSUPPORTED: gcc-9
12
13 // <numeric>
14
15 // Became constexpr in C++20
16 // template<class InputIterator, class OutputIterator, class T>
17 // OutputIterator inclusive_scan(InputIterator first, InputIterator last,
18 // OutputIterator result, T init);
19 //
20
21 #include <numeric>
22 #include <algorithm>
23 #include <array>
24 #include <cassert>
25 #include <functional>
26 #include <iterator>
27
28 #include "test_macros.h"
29 #include "test_iterators.h"
30
31 template <class Iter1, class T>
32 TEST_CONSTEXPR_CXX20 void
test(Iter1 first,Iter1 last,const T * rFirst,const T * rLast)33 test(Iter1 first, Iter1 last, const T *rFirst, const T *rLast)
34 {
35 assert((rLast - rFirst) <= 5); // or else increase the size of "out"
36 T out[5];
37
38 // Not in place
39 T *end = std::inclusive_scan(first, last, out);
40 assert(std::equal(out, end, rFirst, rLast));
41
42 // In place
43 std::copy(first, last, out);
44 end = std::inclusive_scan(out, end, out);
45 assert(std::equal(out, end, rFirst, rLast));
46 }
47
48
49 template <class Iter>
50 TEST_CONSTEXPR_CXX20 void
test()51 test()
52 {
53 int ia[] = {1, 3, 5, 7, 9};
54 const int pRes[] = {1, 4, 9, 16, 25};
55 const unsigned sa = sizeof(ia) / sizeof(ia[0]);
56 static_assert(sa == sizeof(pRes) / sizeof(pRes[0])); // just to be sure
57
58 for (unsigned int i = 0; i < sa; ++i ) {
59 test(Iter(ia), Iter(ia + i), pRes, pRes + i);
60 }
61 }
62
triangle(size_t n)63 constexpr size_t triangle(size_t n) { return n*(n+1)/2; }
64
65 // Basic sanity
66 TEST_CONSTEXPR_CXX20 void
basic_tests()67 basic_tests()
68 {
69 {
70 std::array<size_t, 10> v;
71 std::fill(v.begin(), v.end(), 3);
72 std::inclusive_scan(v.begin(), v.end(), v.begin());
73 for (size_t i = 0; i < v.size(); ++i)
74 assert(v[i] == (i+1) * 3);
75 }
76
77 {
78 std::array<size_t, 10> v;
79 std::iota(v.begin(), v.end(), 0);
80 std::inclusive_scan(v.begin(), v.end(), v.begin());
81 for (size_t i = 0; i < v.size(); ++i)
82 assert(v[i] == triangle(i));
83 }
84
85 {
86 std::array<size_t, 10> v;
87 std::iota(v.begin(), v.end(), 1);
88 std::inclusive_scan(v.begin(), v.end(), v.begin());
89 for (size_t i = 0; i < v.size(); ++i)
90 assert(v[i] == triangle(i + 1));
91 }
92
93 {
94 std::array<size_t, 0> v, res;
95 std::inclusive_scan(v.begin(), v.end(), res.begin());
96 assert(res.empty());
97 }
98 }
99
100 TEST_CONSTEXPR_CXX20 bool
test()101 test()
102 {
103 basic_tests();
104
105 // All the iterator categories
106 test<cpp17_input_iterator <const int*> >();
107 test<forward_iterator <const int*> >();
108 test<bidirectional_iterator<const int*> >();
109 test<random_access_iterator<const int*> >();
110 test<const int*>();
111 test< int*>();
112
113 return true;
114 }
115
main(int,char **)116 int main(int, char**)
117 {
118 test();
119 #if TEST_STD_VER > 17
120 static_assert(test());
121 #endif
122 return 0;
123 }
124