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
11// <numeric>
12
13// Became constexpr in C++20
14// template<class InputIterator, class OutputIterator, class T,
15// class BinaryOperation, class UnaryOperation>
16// OutputIterator transform_inclusive_scan(InputIterator first, InputIterator last,
17// OutputIterator result,
18// BinaryOperation binary_op,
19// UnaryOperation unary_op);
20
21#include <algorithm>
22#include <array>
23#include <cassert>
24#include <cstddef>
25#include <functional>
26#include <numeric>
27
28#include "test_macros.h"
29#include "test_iterators.h"
30
31struct add_one {
32 template <typename T>
33 constexpr T operator()(T x) const {
34 return x + 1;
35 }
36};
37
38template <class Iter1, class BOp, class UOp, class T>
39TEST_CONSTEXPR_CXX20 void
40test(Iter1 first, Iter1 last, BOp bop, UOp uop, const T *rFirst, const T *rLast)
41{
42 assert((rLast - rFirst) <= 5); // or else increase the size of "out"
43 T out[5];
44
45 // Not in place
46 T *end = std::transform_inclusive_scan(first, last, out, bop, uop);
47 assert(std::equal(out, end, rFirst, rLast));
48
49 // In place
50 std::copy(first, last, out);
51 end = std::transform_inclusive_scan(out, end, out, bop, uop);
52 assert(std::equal(out, end, rFirst, rLast));
53}
54
55
56template <class Iter>
57TEST_CONSTEXPR_CXX20 void
58test()
59{
60 int ia[] = { 1, 3, 5, 7, 9 };
61 const int pResI0[] = { 2, 6, 12, 20, 30 }; // with add_one
62 const int mResI0[] = { 2, 8, 48, 384, 3840 };
63 const int pResN0[] = { -1, -4, -9, -16, -25 }; // with negate
64 const int mResN0[] = { -1, 3, -15, 105, -945 };
65 const unsigned sa = sizeof(ia) / sizeof(ia[0] );
66 static_assert(sa == sizeof(pResI0) / sizeof(pResI0[0])); // just to be sure
67 static_assert(sa == sizeof(mResI0) / sizeof(mResI0[0])); // just to be sure
68 static_assert(sa == sizeof(pResN0) / sizeof(pResN0[0])); // just to be sure
69 static_assert(sa == sizeof(mResN0) / sizeof(mResN0[0])); // just to be sure
70
71 for (unsigned int i = 0; i < sa; ++i ) {
72 test(Iter(ia), Iter(ia + i), std::plus<>(), add_one{}, pResI0, pResI0 + i);
73 test(Iter(ia), Iter(ia + i), std::multiplies<>(), add_one{}, mResI0, mResI0 + i);
74 test(Iter(ia), Iter(ia + i), std::plus<>(), std::negate<>(), pResN0, pResN0 + i);
75 test(Iter(ia), Iter(ia + i), std::multiplies<>(), std::negate<>(), mResN0, mResN0 + i);
76 }
77}
78
79constexpr std::size_t triangle(size_t n) { return n*(n+1)/2; }
80
81// Basic sanity
82TEST_CONSTEXPR_CXX20 void
83basic_tests()
84{
85 {
86 std::array<std::size_t, 10> v;
87 std::fill(first: v.begin(), last: v.end(), value: 3);
88 std::transform_inclusive_scan(first: v.begin(), last: v.end(), result: v.begin(), binary_op: std::plus<>(), unary_op: add_one{});
89 for (std::size_t i = 0; i < v.size(); ++i)
90 assert(v[i] == (i+1) * 4);
91 }
92
93 {
94 std::array<std::size_t, 10> v;
95 std::iota(first: v.begin(), last: v.end(), value: 0);
96 std::transform_inclusive_scan(first: v.begin(), last: v.end(), result: v.begin(), binary_op: std::plus<>(), unary_op: add_one{});
97 for (std::size_t i = 0; i < v.size(); ++i)
98 assert(v[i] == triangle(i) + i + 1);
99 }
100
101 {
102 std::array<std::size_t, 10> v;
103 std::iota(first: v.begin(), last: v.end(), value: 1);
104 std::transform_inclusive_scan(first: v.begin(), last: v.end(), result: v.begin(), binary_op: std::plus<>(), unary_op: add_one{});
105 for (std::size_t i = 0; i < v.size(); ++i)
106 assert(v[i] == triangle(i + 1) + i + 1);
107 }
108
109 {
110 std::array<std::size_t, 0> v, res;
111 std::transform_inclusive_scan(first: v.begin(), last: v.end(), result: res.begin(), binary_op: std::plus<>(), unary_op: add_one{});
112 assert(res.empty());
113 }
114}
115
116TEST_CONSTEXPR_CXX20 bool
117test()
118{
119 basic_tests();
120
121// All the iterator categories
122 test<cpp17_input_iterator <const int*> >();
123 test<forward_iterator <const int*> >();
124 test<bidirectional_iterator<const int*> >();
125 test<random_access_iterator<const int*> >();
126 test<const int*>();
127 test< int*>();
128
129 return true;
130}
131
132int main(int, char**)
133{
134 test();
135#if TEST_STD_VER > 17
136 static_assert(test());
137#endif
138 return 0;
139}
140

source code of libcxx/test/std/numerics/numeric.ops/transform.inclusive.scan/transform_inclusive_scan_bop_uop.pass.cpp