struct.mcd.nested.cpp
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// Copyright Louis Dionne 2013-2022
// 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/concept/struct.hpp>
#include <boost/hana/config.hpp>
#include <boost/hana/equal.hpp>
#include <boost/hana/find.hpp>
#include <boost/hana/functional/id.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 {
std::string name;
int age;
struct hana_accessors_impl {
static BOOST_HANA_CONSTEXPR_LAMBDA auto apply() {
return boost::hana::make_tuple(
boost::hana::make_pair(BOOST_HANA_STRING("name"),
[](auto&& p) -> decltype(auto) {
return boost::hana::id(std::forward<decltype(p)>(p).name);
}),
boost::hana::make_pair(BOOST_HANA_STRING("age"),
[](auto&& p) -> decltype(auto) {
return boost::hana::id(std::forward<decltype(p)>(p).age);
})
);
}
};
};
//! [main]
int main() {
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, BOOST_HANA_STRING("name")) == hana::just("John"));
BOOST_HANA_RUNTIME_CHECK(hana::find(john, BOOST_HANA_STRING("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(BOOST_HANA_STRING("name"), "John"),
hana::make_pair(BOOST_HANA_STRING("age"), 30)
));
}