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/accessors.hpp>
6 #include <boost/hana/assert.hpp>
7 #include <boost/hana/at.hpp>
8 #include <boost/hana/define_struct.hpp>
9 #include <boost/hana/equal.hpp>
10 #include <boost/hana/first.hpp>
11 #include <boost/hana/integral_constant.hpp>
12 #include <boost/hana/second.hpp>
13 #include <boost/hana/string.hpp>
14 
15 #include <string>
16 namespace hana = boost::hana;
17 
18 
19 struct Person {
20     BOOST_HANA_DEFINE_STRUCT(Person,
21         (std::string, name),
22         (unsigned short, age)
23     );
24 };
25 
main()26 int main() {
27     constexpr auto accessors = hana::accessors<Person>();
28     BOOST_HANA_CONSTANT_CHECK(
29         hana::first(accessors[hana::size_c<0>]) == BOOST_HANA_STRING("name")
30     );
31 
32     BOOST_HANA_CONSTANT_CHECK(
33         hana::first(accessors[hana::size_c<1>]) == BOOST_HANA_STRING("age")
34     );
35 
36     constexpr auto get_name = hana::second(accessors[hana::size_c<0>]);
37     constexpr auto get_age = hana::second(accessors[hana::size_c<1>]);
38 
39     Person john{"John", 30};
40     BOOST_HANA_RUNTIME_CHECK(get_name(john) == "John");
41     BOOST_HANA_RUNTIME_CHECK(get_age(john) == 30);
42 }
43