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/assert.hpp>
6#include <boost/hana/equal.hpp>
7#include <boost/hana/ext/std/integer_sequence.hpp>
8#include <boost/hana/ext/std/integral_constant.hpp>
9#include <boost/hana/find_if.hpp>
10#include <boost/hana/optional.hpp>
11
12#include <cstddef>
13#include <type_traits>
14#include <utility>
15namespace hana = boost::hana;
16
17
18struct undefined { };
19
20
21int main() {
22 BOOST_HANA_CONSTANT_CHECK(hana::equal(
23 hana::find_if(std::index_sequence<>{},
24 hana::equal.to(undefined{})),
25 hana::nothing
26 ));
27
28 BOOST_HANA_CONSTANT_CHECK(hana::equal(
29 hana::find_if(std::index_sequence<0>{},
30 hana::equal.to(std::integral_constant<std::size_t, 0>{})),
31 hana::just(std::integral_constant<std::size_t, 0>{})
32 ));
33 BOOST_HANA_CONSTANT_CHECK(hana::equal(
34 hana::find_if(std::index_sequence<0>{},
35 hana::equal.to(std::integral_constant<std::size_t, 1>{})),
36 hana::nothing
37 ));
38
39 BOOST_HANA_CONSTANT_CHECK(hana::equal(
40 hana::find_if(std::index_sequence<0, 1>{},
41 hana::equal.to(std::integral_constant<std::size_t, 0>{})),
42 hana::just(std::integral_constant<std::size_t, 0>{})
43 ));
44 BOOST_HANA_CONSTANT_CHECK(hana::equal(
45 hana::find_if(std::index_sequence<0, 1>{},
46 hana::equal.to(std::integral_constant<std::size_t, 1>{})),
47 hana::just(std::integral_constant<std::size_t, 1>{})
48 ));
49 BOOST_HANA_CONSTANT_CHECK(hana::equal(
50 hana::find_if(std::index_sequence<0, 1>{},
51 hana::equal.to(std::integral_constant<std::size_t, 2>{})),
52 hana::nothing
53 ));
54
55 BOOST_HANA_CONSTANT_CHECK(hana::equal(
56 hana::find_if(std::index_sequence<0, 1, 2>{},
57 hana::equal.to(std::integral_constant<std::size_t, 0>{})),
58 hana::just(std::integral_constant<std::size_t, 0>{})
59 ));
60 BOOST_HANA_CONSTANT_CHECK(hana::equal(
61 hana::find_if(std::index_sequence<0, 1, 2>{},
62 hana::equal.to(std::integral_constant<std::size_t, 1>{})),
63 hana::just(std::integral_constant<std::size_t, 1>{})
64 ));
65 BOOST_HANA_CONSTANT_CHECK(hana::equal(
66 hana::find_if(std::index_sequence<0, 1, 2>{},
67 hana::equal.to(std::integral_constant<std::size_t, 2>{})),
68 hana::just(std::integral_constant<std::size_t, 2>{})
69 ));
70 BOOST_HANA_CONSTANT_CHECK(hana::equal(
71 hana::find_if(std::index_sequence<0, 1, 2>{},
72 hana::equal.to(std::integral_constant<std::size_t, 3>{})),
73 hana::nothing
74 ));
75
76 BOOST_HANA_CONSTANT_CHECK(hana::equal(
77 hana::find_if(std::index_sequence<0, 1, 2, 3>{},
78 hana::equal.to(std::integral_constant<std::size_t, 0>{})),
79 hana::just(std::integral_constant<std::size_t, 0>{})
80 ));
81 BOOST_HANA_CONSTANT_CHECK(hana::equal(
82 hana::find_if(std::index_sequence<0, 1, 2, 3>{},
83 hana::equal.to(std::integral_constant<std::size_t, 1>{})),
84 hana::just(std::integral_constant<std::size_t, 1>{})
85 ));
86 BOOST_HANA_CONSTANT_CHECK(hana::equal(
87 hana::find_if(std::index_sequence<0, 1, 2, 3>{},
88 hana::equal.to(std::integral_constant<std::size_t, 2>{})),
89 hana::just(std::integral_constant<std::size_t, 2>{})
90 ));
91 BOOST_HANA_CONSTANT_CHECK(hana::equal(
92 hana::find_if(std::index_sequence<0, 1, 2, 3>{},
93 hana::equal.to(std::integral_constant<std::size_t, 3>{})),
94 hana::just(std::integral_constant<std::size_t, 3>{})
95 ));
96 BOOST_HANA_CONSTANT_CHECK(hana::equal(
97 hana::find_if(std::index_sequence<0, 1, 2, 3>{},
98 hana::equal.to(std::integral_constant<std::size_t, 4>{})),
99 hana::nothing
100 ));
101}
102

source code of boost/libs/hana/test/ext/std/integer_sequence/find_if.cpp