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/at_key.hpp>
7#include <boost/hana/equal.hpp>
8#include <boost/hana/map.hpp>
9
10#include <laws/base.hpp>
11#include <support/minimal_product.hpp>
12
13#include <utility>
14namespace hana = boost::hana;
15
16
17template <int i>
18auto key() { return hana::test::ct_eq<i>{}; }
19
20template <int i>
21auto val() { return hana::test::ct_eq<-i>{}; }
22
23template <int i, int j>
24auto p() { return ::minimal_product(key<i>(), val<j>()); }
25
26int main() {
27 BOOST_HANA_CONSTANT_CHECK(hana::equal(
28 hana::at_key(hana::make_map(p<0, 0>()), key<0>()),
29 val<0>()
30 ));
31
32 BOOST_HANA_CONSTANT_CHECK(hana::equal(
33 hana::at_key(hana::make_map(p<0, 0>(), p<1,1>()), key<0>()),
34 val<0>()
35 ));
36 BOOST_HANA_CONSTANT_CHECK(hana::equal(
37 hana::at_key(hana::make_map(p<0, 0>(), p<1,1>()), key<1>()),
38 val<1>()
39 ));
40
41 BOOST_HANA_CONSTANT_CHECK(hana::equal(
42 hana::at_key(hana::make_map(p<0, 0>(), p<1,1>(), p<2,2>()), key<0>()),
43 val<0>()
44 ));
45 BOOST_HANA_CONSTANT_CHECK(hana::equal(
46 hana::at_key(hana::make_map(p<0, 0>(), p<1,1>(), p<2,2>()), key<1>()),
47 val<1>()
48 ));
49 BOOST_HANA_CONSTANT_CHECK(hana::equal(
50 hana::at_key(hana::make_map(p<0, 0>(), p<1,1>(), p<2,2>()), key<2>()),
51 val<2>()
52 ));
53
54 // check operators
55 auto m = hana::make_map(p<2, 2>(), p<1, 1>());
56 auto const const_m = hana::make_map(p<2, 2>(), p<1, 1>());
57 BOOST_HANA_CONSTANT_CHECK(hana::equal(m[key<1>()], val<1>()));
58 BOOST_HANA_CONSTANT_CHECK(hana::equal(const_m[key<1>()], val<1>()));
59 BOOST_HANA_CONSTANT_CHECK(hana::equal(std::move(m)[key<1>()], val<1>()));
60}
61

source code of boost/libs/hana/test/map/at_key.cpp