hana/example/comparing.cpp
2017-01-07 14:14:18 -08:00

41 lines
1.2 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/comparing.hpp>
#include <boost/hana/equal.hpp>
#include <boost/hana/group.hpp>
#include <boost/hana/length.hpp>
#include <boost/hana/range.hpp>
#include <boost/hana/tuple.hpp>
namespace hana = boost::hana;
int main() {
constexpr auto sequences = hana::make_tuple(
hana::make_tuple(1, 2, 3),
hana::make_tuple('x', 'y', 'z'),
hana::range_c<long, 0, 1>,
hana::tuple_t<char, int>,
hana::range_c<int, 0, 2>,
hana::make_tuple(123.4, nullptr)
);
constexpr auto grouped = hana::group.by(hana::comparing(hana::length), sequences);
static_assert(grouped == hana::make_tuple(
hana::make_tuple(
hana::make_tuple(1, 2, 3),
hana::make_tuple('x', 'y', 'z')
),
hana::make_tuple(
hana::range_c<long, 0, 1>
),
hana::make_tuple(
hana::tuple_t<char, int>,
hana::range_c<int, 0, 2>,
hana::make_tuple(123.4, nullptr)
)
), "");
}