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// 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 {
std::string name;
int age;
};
// The keys can be anything as long as they are compile-time comparable.
constexpr auto name = hana::integral_c<std::string Person::*, &Person::name>;
constexpr auto age = hana::string_c<'a', 'g', 'e'>;
namespace boost { namespace hana {
template <>
struct accessors_impl<Person> {
static BOOST_HANA_CONSTEXPR_LAMBDA auto apply() {
return make_tuple(
make_pair(name, [](auto&& p) -> decltype(auto) {
return id(std::forward<decltype(p)>(p).name);
}),
make_pair(age, [](auto&& p) -> decltype(auto) {
return 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, 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)
));
}
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