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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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