1// Copyright Louis Dionne 2013-2022
2// Distributed under the Boost Software License, Version 1.0.
3// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
4
5#include <boost/hana/functional/iterate.hpp>
6
7#include <boost/hana/assert.hpp>
8#include <boost/hana/equal.hpp>
9
10#include <laws/base.hpp>
11
12#include <vector>
13namespace hana = boost::hana;
14using hana::test::ct_eq;
15
16
17struct undefined { };
18
19constexpr int incr(int i) { return i + 1; }
20
21int main() {
22 hana::test::_injection<0> f{};
23
24 // "real usage" tests
25 static_assert(hana::iterate<3>(incr, 0) == 3, "");
26 {
27 std::vector<int> vec;
28 hana::iterate<10>([&](int i) { vec.push_back(x: i); return i + 1; }, 0);
29 BOOST_HANA_RUNTIME_CHECK(
30 vec == std::vector<int>{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}
31 );
32 }
33
34 // equivalence between iterate<n>(f, x) and iterate<n>(f)(x)
35 BOOST_HANA_CONSTANT_CHECK(hana::equal(
36 hana::iterate<0>(undefined{})(ct_eq<0>{}),
37 hana::iterate<0>(undefined{}, ct_eq<0>{})
38 ));
39
40 BOOST_HANA_CONSTANT_CHECK(hana::equal(
41 hana::iterate<4>(f)(ct_eq<0>{}),
42 hana::iterate<4>(f, ct_eq<0>{})
43 ));
44
45 BOOST_HANA_CONSTANT_CHECK(hana::equal(
46 hana::iterate<10>(f)(ct_eq<0>{}),
47 hana::iterate<10>(f, ct_eq<0>{})
48 ));
49
50 // systematic tests
51 BOOST_HANA_CONSTANT_CHECK(hana::equal(
52 hana::iterate<0>(undefined{}, ct_eq<0>{}),
53 ct_eq<0>{}
54 ));
55
56 BOOST_HANA_CONSTANT_CHECK(hana::equal(
57 hana::iterate<1>(f, ct_eq<0>{}),
58 f(ct_eq<0>{})
59 ));
60
61 BOOST_HANA_CONSTANT_CHECK(hana::equal(
62 hana::iterate<2>(f, ct_eq<0>{}),
63 f(f(ct_eq<0>{}))
64 ));
65
66 BOOST_HANA_CONSTANT_CHECK(hana::equal(
67 hana::iterate<3>(f, ct_eq<0>{}),
68 f(f(f(ct_eq<0>{})))
69 ));
70
71 BOOST_HANA_CONSTANT_CHECK(hana::equal(
72 hana::iterate<4>(f, ct_eq<0>{}),
73 f(f(f(f(ct_eq<0>{}))))
74 ));
75
76 BOOST_HANA_CONSTANT_CHECK(hana::equal(
77 hana::iterate<5>(f, ct_eq<0>{}),
78 f(f(f(f(f(ct_eq<0>{})))))
79 ));
80
81 BOOST_HANA_CONSTANT_CHECK(hana::equal(
82 hana::iterate<6>(f, ct_eq<0>{}),
83 f(f(f(f(f(f(ct_eq<0>{}))))))
84 ));
85
86 BOOST_HANA_CONSTANT_CHECK(hana::equal(
87 hana::iterate<7>(f, ct_eq<0>{}),
88 f(f(f(f(f(f(f(ct_eq<0>{})))))))
89 ));
90
91 BOOST_HANA_CONSTANT_CHECK(hana::equal(
92 hana::iterate<11>(f, ct_eq<0>{}),
93 f(f(f(f(f(f(f(f(f(f(f(ct_eq<0>{})))))))))))
94 ));
95
96 BOOST_HANA_CONSTANT_CHECK(hana::equal(
97 hana::iterate<12>(f, ct_eq<0>{}),
98 f(f(f(f(f(f(f(f(f(f(f(f(ct_eq<0>{}))))))))))))
99 ));
100
101 BOOST_HANA_CONSTANT_CHECK(hana::equal(
102 hana::iterate<13>(f, ct_eq<0>{}),
103 f(f(f(f(f(f(f(f(f(f(f(f(f(ct_eq<0>{})))))))))))))
104 ));
105
106 // We can't nest too many calls to f, because that uses a hana::tuple
107 // internally and some implementation (libstdc++) have trouble with
108 // deeply-nested calls to `std::is_constructible`, which is required by
109 // hana::tuple. Hence, we use an homogeneous function for the remaining
110 // tests.
111 static_assert(hana::iterate<23>(incr, 0) == 23, "");
112 static_assert(hana::iterate<24>(incr, 0) == 24, "");
113 static_assert(hana::iterate<25>(incr, 0) == 25, "");
114 static_assert(hana::iterate<26>(incr, 0) == 26, "");
115 static_assert(hana::iterate<27>(incr, 0) == 27, "");
116 static_assert(hana::iterate<28>(incr, 0) == 28, "");
117 static_assert(hana::iterate<29>(incr, 0) == 29, "");
118
119 static_assert(hana::iterate<30>(incr, 0) == 30, "");
120 static_assert(hana::iterate<31>(incr, 0) == 31, "");
121 static_assert(hana::iterate<32>(incr, 0) == 32, "");
122 static_assert(hana::iterate<33>(incr, 0) == 33, "");
123 static_assert(hana::iterate<34>(incr, 0) == 34, "");
124 static_assert(hana::iterate<35>(incr, 0) == 35, "");
125 static_assert(hana::iterate<36>(incr, 0) == 36, "");
126 static_assert(hana::iterate<37>(incr, 0) == 37, "");
127 static_assert(hana::iterate<38>(incr, 0) == 38, "");
128 static_assert(hana::iterate<39>(incr, 0) == 39, "");
129
130 static_assert(hana::iterate<40>(incr, 0) == 40, "");
131 static_assert(hana::iterate<41>(incr, 0) == 41, "");
132 static_assert(hana::iterate<42>(incr, 0) == 42, "");
133 static_assert(hana::iterate<43>(incr, 0) == 43, "");
134 static_assert(hana::iterate<44>(incr, 0) == 44, "");
135 static_assert(hana::iterate<45>(incr, 0) == 45, "");
136 static_assert(hana::iterate<46>(incr, 0) == 46, "");
137 static_assert(hana::iterate<47>(incr, 0) == 47, "");
138 static_assert(hana::iterate<48>(incr, 0) == 48, "");
139 static_assert(hana::iterate<49>(incr, 0) == 49, "");
140
141 static_assert(hana::iterate<50>(incr, 0) == 50, "");
142 static_assert(hana::iterate<51>(incr, 0) == 51, "");
143 static_assert(hana::iterate<52>(incr, 0) == 52, "");
144 static_assert(hana::iterate<53>(incr, 0) == 53, "");
145 static_assert(hana::iterate<54>(incr, 0) == 54, "");
146 static_assert(hana::iterate<55>(incr, 0) == 55, "");
147 static_assert(hana::iterate<56>(incr, 0) == 56, "");
148 static_assert(hana::iterate<57>(incr, 0) == 57, "");
149 static_assert(hana::iterate<58>(incr, 0) == 58, "");
150 static_assert(hana::iterate<59>(incr, 0) == 59, "");
151}
152

source code of boost/libs/hana/test/functional/iterate.cpp