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

65 lines
1.8 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/assert.hpp>
#include <boost/hana/comparing.hpp>
#include <boost/hana/equal.hpp>
#include <boost/hana/group.hpp>
#include <boost/hana/integral_constant.hpp>
#include <boost/hana/length.hpp>
#include <boost/hana/range.hpp>
#include <boost/hana/tuple.hpp>
#include <boost/hana/type.hpp>
namespace hana = boost::hana;
// group without a predicate
BOOST_HANA_CONSTANT_CHECK(
hana::group(hana::make_tuple(hana::int_c<1>, hana::long_c<1>, hana::type_c<int>, hana::char_c<'x'>, hana::char_c<'x'>))
== hana::make_tuple(
hana::make_tuple(hana::int_c<1>, hana::long_c<1>),
hana::make_tuple(hana::type_c<int>),
hana::make_tuple(hana::char_c<'x'>, hana::char_c<'x'>)
)
);
// group with a predicate
constexpr auto tuples = hana::make_tuple(
hana::range_c<int, 0, 1>,
hana::range_c<int, 0, 2>,
hana::range_c<int, 1, 3>,
hana::range_c<int, 2, 6>
);
BOOST_HANA_CONSTANT_CHECK(
hana::group(tuples, hana::comparing(hana::length))
== hana::make_tuple(
hana::make_tuple(
hana::range_c<int, 0, 1>
),
hana::make_tuple(
hana::range_c<int, 0, 2>,
hana::range_c<int, 1, 3>
),
hana::make_tuple(
hana::range_c<int, 2, 6>
)
)
);
// group.by is syntactic sugar
static_assert(
hana::group.by(hana::comparing(hana::typeid_),
hana::make_tuple(1, 2, 3, 'x', 'y', 4.4, 5.5))
== hana::make_tuple(
hana::make_tuple(1, 2, 3),
hana::make_tuple('x', 'y'),
hana::make_tuple(4.4, 5.5)
)
, "");
int main() { }