mirror of
https://github.com/boostorg/hana.git
synced 2026-01-22 05:12:35 +00:00
68 lines
1.6 KiB
C++
68 lines
1.6 KiB
C++
/*
|
|
@copyright Louis Dionne 2015
|
|
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 <iostream>
|
|
#include <string>
|
|
#include <tuple>
|
|
#include <type_traits>
|
|
|
|
#include <boost/hana/ext/std/type_traits.hpp>
|
|
|
|
//! [includes]
|
|
#include <boost/hana.hpp>
|
|
using namespace boost::hana;
|
|
//! [includes]
|
|
|
|
|
|
int main() {
|
|
|
|
// IMPORTANT NOTE:
|
|
// When changing this, make sure the corresponding changes are propagated
|
|
// to `example/tutorial/amphi.cpp`.
|
|
|
|
//! [decls]
|
|
struct Person { std::string name; };
|
|
struct Car { std::string name; };
|
|
struct City { std::string name; };
|
|
//! [decls]
|
|
|
|
//! [make_tuple]
|
|
auto stuff = make_tuple(Person{"Louis"}, Car{"Toyota"}, City{"Quebec"});
|
|
//! [make_tuple]
|
|
|
|
{
|
|
//! [_tuple]
|
|
_tuple<Person, Car, City> stuff{Person{"Louis"}, Car{"Toyota"}, City{"Quebec"}};
|
|
//! [_tuple]
|
|
}
|
|
|
|
//! [basic_operations]
|
|
Car& car = at_c<1>(stuff);
|
|
// BOOST_HANA_RUNTIME_CHECK is equivalent to assert
|
|
BOOST_HANA_RUNTIME_CHECK(car.name == "Toyota");
|
|
static_assert(length(stuff) == 3u, "");
|
|
//! [basic_operations]
|
|
|
|
//! [transform]
|
|
_tuple<std::string, std::string, std::string> names = transform(stuff, [](auto x) { return x.name; });
|
|
BOOST_HANA_RUNTIME_CHECK(names == make_tuple("Louis", "Toyota", "Quebec"));
|
|
//! [transform]
|
|
|
|
//! [metafunction]
|
|
using namespace traits; // bring in remove_cv and add_pointer
|
|
|
|
auto F = [](auto T) { // just pretend T is a type
|
|
return add_pointer(remove_cv(T));
|
|
};
|
|
//! [metafunction]
|
|
|
|
//! [type]
|
|
// BOOST_HANA_CONSTANT_CHECK is almost equivalent to static_assert
|
|
BOOST_HANA_CONSTANT_CHECK(F(type<int const>) == type<int*>);
|
|
//! [type]
|
|
|
|
}
|