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

69 lines
2.0 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/config.hpp>
#include <boost/hana/core/to.hpp>
#include <boost/hana/equal.hpp>
#include <boost/hana/find.hpp>
#include <boost/hana/functional/id.hpp>
#include <boost/hana/fwd/accessors.hpp>
#include <boost/hana/integral_constant.hpp>
#include <boost/hana/not_equal.hpp>
#include <boost/hana/pair.hpp>
#include <boost/hana/string.hpp>
#include <boost/hana/tuple.hpp>
#include <string>
#include <utility>
namespace hana = boost::hana;
//! [main]
struct Person {
Person(std::string const& name, int age) : name_(name), age_(age) { }
std::string const& get_name() const { return name_; }
int get_age() const { return age_; }
private:
std::string name_;
int age_;
};
namespace boost { namespace hana {
template <>
struct accessors_impl<Person> {
static BOOST_HANA_CONSTEXPR_LAMBDA auto apply() {
return make_tuple(
make_pair(BOOST_HANA_STRING("name"), [](auto&& p) -> std::string const& {
return p.get_name();
}),
make_pair(BOOST_HANA_STRING("age"), [](auto&& p) {
return p.get_age();
})
);
}
};
}}
//! [main]
int main() {
auto name = BOOST_HANA_STRING("name");
auto age = BOOST_HANA_STRING("age");
Person john{"John", 30}, bob{"Bob", 40};
BOOST_HANA_RUNTIME_CHECK(hana::equal(john, john));
BOOST_HANA_RUNTIME_CHECK(hana::not_equal(john, bob));
BOOST_HANA_RUNTIME_CHECK(hana::find(john, name) == hana::just("John"));
BOOST_HANA_RUNTIME_CHECK(hana::find(john, age) == hana::just(30));
BOOST_HANA_CONSTANT_CHECK(hana::find(john, BOOST_HANA_STRING("foo")) == hana::nothing);
BOOST_HANA_RUNTIME_CHECK(hana::to_tuple(john) == hana::make_tuple(
hana::make_pair(name, "John"),
hana::make_pair(age, 30)
));
}