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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)
5 #include <boost/hana/assert.hpp>
6 #include <boost/hana/equal.hpp>
7 #include <boost/hana/equal.hpp>
8 #include <boost/hana/ext/std/integral_constant.hpp>
9 #include <boost/hana/find_if.hpp>
10 #include <boost/hana/functional/compose.hpp>
11 #include <boost/hana/optional.hpp>
12 #include <boost/hana/tuple.hpp>
13 #include <boost/hana/type.hpp>
15 #include <type_traits>
16 namespace hana
= boost::hana
;
19 // First get the type of the object, and then call the trait on it.
20 constexpr auto is_integral
= hana::compose(hana::trait
<std::is_integral
>, hana::typeid_
);
21 constexpr auto is_class
= hana::compose(hana::trait
<std::is_class
>, hana::typeid_
);
24 hana::find_if(hana::make_tuple(1.0, 2, '3'), is_integral
) == hana::just(2)
27 BOOST_HANA_CONSTANT_CHECK(
28 hana::find_if(hana::make_tuple(1.0, 2, '3'), is_class
) == hana::nothing
31 constexpr auto types
= hana::tuple_t
<char, int, unsigned, long, unsigned long>;
32 BOOST_HANA_CONSTANT_CHECK(
33 hana::find_if(types
, hana::equal
.to(hana::type_c
<unsigned>)) == hana::just(hana::type_c
<unsigned>)
35 BOOST_HANA_CONSTANT_CHECK(
36 hana::find_if(types
, hana::equal
.to(hana::type_c
<void>)) == hana::nothing