hana/example/accessors.cpp
2017-01-07 14:14:18 -08:00

43 lines
1.2 KiB
C++

// Copyright Louis Dionne 2013-2017
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
#include <boost/hana/accessors.hpp>
#include <boost/hana/assert.hpp>
#include <boost/hana/at.hpp>
#include <boost/hana/define_struct.hpp>
#include <boost/hana/equal.hpp>
#include <boost/hana/first.hpp>
#include <boost/hana/integral_constant.hpp>
#include <boost/hana/second.hpp>
#include <boost/hana/string.hpp>
#include <string>
namespace hana = boost::hana;
struct Person {
BOOST_HANA_DEFINE_STRUCT(Person,
(std::string, name),
(unsigned short, age)
);
};
int main() {
constexpr auto accessors = hana::accessors<Person>();
BOOST_HANA_CONSTANT_CHECK(
hana::first(accessors[hana::size_c<0>]) == BOOST_HANA_STRING("name")
);
BOOST_HANA_CONSTANT_CHECK(
hana::first(accessors[hana::size_c<1>]) == BOOST_HANA_STRING("age")
);
constexpr auto get_name = hana::second(accessors[hana::size_c<0>]);
constexpr auto get_age = hana::second(accessors[hana::size_c<1>]);
Person john{"John", 30};
BOOST_HANA_RUNTIME_CHECK(get_name(john) == "John");
BOOST_HANA_RUNTIME_CHECK(get_age(john) == 30);
}