hana/example/tutorial/introspection.adapt.cpp
2017-01-07 14:14:18 -08:00

101 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.hpp>
#include <iostream>
#include <string>
namespace hana = boost::hana;
using namespace hana::literals;
using namespace std::literals;
//! [BOOST_HANA_DEFINE_STRUCT]
struct Person {
BOOST_HANA_DEFINE_STRUCT(Person,
(std::string, name),
(int, age)
);
};
//! [BOOST_HANA_DEFINE_STRUCT]
int main() {
//! [for_each]
Person john{"John", 30};
hana::for_each(john, [](auto pair) {
std::cout << hana::to<char const*>(hana::first(pair)) << ": "
<< hana::second(pair) << std::endl;
});
// name: John
// age: 30
//! [for_each]
//! [for_each.fuse]
hana::for_each(john, hana::fuse([](auto name, auto member) {
std::cout << hana::to<char const*>(name) << ": " << member << std::endl;
}));
//! [for_each.fuse]
#ifdef BOOST_HANA_CONFIG_ENABLE_STRING_UDL
{
//! [at_key]
std::string name = hana::at_key(john, "name"_s);
BOOST_HANA_RUNTIME_CHECK(name == "John");
int age = hana::at_key(john, "age"_s);
BOOST_HANA_RUNTIME_CHECK(age == 30);
//! [at_key]
}{
//! [to<map_tag>]
auto map = hana::insert(hana::to<hana::map_tag>(john), hana::make_pair("last name"_s, "Doe"s));
std::string name = map["name"_s];
BOOST_HANA_RUNTIME_CHECK(name == "John");
std::string last_name = map["last name"_s];
BOOST_HANA_RUNTIME_CHECK(last_name == "Doe");
int age = map["age"_s];
BOOST_HANA_RUNTIME_CHECK(age == 30);
//! [to<map_tag>]
}
#endif
}
//! [BOOST_HANA_ADAPT_STRUCT]
namespace not_my_namespace {
struct Person {
std::string name;
int age;
};
}
BOOST_HANA_ADAPT_STRUCT(not_my_namespace::Person, name, age);
//! [BOOST_HANA_ADAPT_STRUCT]
//! [BOOST_HANA_ADAPT_ADT]
namespace also_not_my_namespace {
struct Person {
std::string get_name();
int get_age();
};
}
BOOST_HANA_ADAPT_ADT(also_not_my_namespace::Person,
(name, [](auto const& p) { return p.get_name(); }),
(age, [](auto const& p) { return p.get_age(); })
);
//! [BOOST_HANA_ADAPT_ADT]