hana/test/concept/struct/at_key.cpp
2017-01-07 14:14:18 -08:00

56 lines
1.6 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/assert.hpp>
#include <boost/hana/at_key.hpp>
#include <boost/hana/define_struct.hpp>
#include <boost/hana/string.hpp>
#include <string>
namespace hana = boost::hana;
struct Person {
BOOST_HANA_DEFINE_STRUCT(Person,
(std::string, name),
(std::string, last_name),
(int, age)
);
};
int main() {
// non-const ref
{
Person john{"John", "Doe", 30};
std::string& name = hana::at_key(john, BOOST_HANA_STRING("name"));
std::string& last_name = hana::at_key(john, BOOST_HANA_STRING("last_name"));
int& age = hana::at_key(john, BOOST_HANA_STRING("age"));
name = "Bob";
last_name = "Foo";
age = 99;
BOOST_HANA_RUNTIME_CHECK(john.name == "Bob");
BOOST_HANA_RUNTIME_CHECK(john.last_name == "Foo");
BOOST_HANA_RUNTIME_CHECK(john.age == 99);
}
// const ref
{
Person john{"John", "Doe", 30};
Person const& const_john = john;
std::string const& name = hana::at_key(const_john, BOOST_HANA_STRING("name"));
std::string const& last_name = hana::at_key(const_john, BOOST_HANA_STRING("last_name"));
int const& age = hana::at_key(const_john, BOOST_HANA_STRING("age"));
john.name = "Bob";
john.last_name = "Foo";
john.age = 99;
BOOST_HANA_RUNTIME_CHECK(name == "Bob");
BOOST_HANA_RUNTIME_CHECK(last_name == "Foo");
BOOST_HANA_RUNTIME_CHECK(age == 99);
}
}