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/at_key.hpp>
7 #include <boost/hana/define_struct.hpp>
8 #include <boost/hana/string.hpp>
9
10 #include <string>
11 namespace hana = boost::hana;
12
13
14 struct Person {
15 BOOST_HANA_DEFINE_STRUCT(Person,
16 (std::string, name),
17 (std::string, last_name),
18 (int, age)
19 );
20 };
21
main()22 int main() {
23 // non-const ref
24 {
25 Person john{"John", "Doe", 30};
26 std::string& name = hana::at_key(john, BOOST_HANA_STRING("name"));
27 std::string& last_name = hana::at_key(john, BOOST_HANA_STRING("last_name"));
28 int& age = hana::at_key(john, BOOST_HANA_STRING("age"));
29
30 name = "Bob";
31 last_name = "Foo";
32 age = 99;
33
34 BOOST_HANA_RUNTIME_CHECK(john.name == "Bob");
35 BOOST_HANA_RUNTIME_CHECK(john.last_name == "Foo");
36 BOOST_HANA_RUNTIME_CHECK(john.age == 99);
37 }
38
39 // const ref
40 {
41 Person john{"John", "Doe", 30};
42 Person const& const_john = john;
43 std::string const& name = hana::at_key(const_john, BOOST_HANA_STRING("name"));
44 std::string const& last_name = hana::at_key(const_john, BOOST_HANA_STRING("last_name"));
45 int const& age = hana::at_key(const_john, BOOST_HANA_STRING("age"));
46
47 john.name = "Bob";
48 john.last_name = "Foo";
49 john.age = 99;
50
51 BOOST_HANA_RUNTIME_CHECK(name == "Bob");
52 BOOST_HANA_RUNTIME_CHECK(last_name == "Foo");
53 BOOST_HANA_RUNTIME_CHECK(age == 99);
54 }
55 }
56