1 // Copyright Louis Dionne 2013-2017
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/find_if.hpp>
8 #include <boost/hana/optional.hpp>
9
10 #include <laws/base.hpp>
11 namespace hana = boost::hana;
12 using hana::test::ct_eq;
13
14
main()15 int main() {
16 ct_eq<2> x{};
17 ct_eq<3> y{};
18
19 BOOST_HANA_CONSTANT_CHECK(hana::equal(
20 hana::find_if(hana::just(x), hana::equal.to(x)),
21 hana::just(x)
22 ));
23 BOOST_HANA_CONSTANT_CHECK(hana::equal(
24 hana::find_if(hana::just(x), hana::equal.to(y)),
25 hana::nothing
26 ));
27 BOOST_HANA_CONSTANT_CHECK(hana::equal(
28 hana::find_if(hana::nothing, hana::equal.to(x)),
29 hana::nothing
30 ));
31
32 // Previously, there was a bug that would make this fail.
33 auto non_const_nothing = hana::nothing;
34 BOOST_HANA_CONSTANT_CHECK(hana::equal(
35 hana::find_if(non_const_nothing, hana::equal.to(x)),
36 hana::nothing
37 ));
38 }
39