hana/test/ext/std/integer_sequence/iterable.cpp

/*
@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 <boost/hana/ext/std/integer_sequence.hpp>
#include <boost/hana/ext/std/integral_constant.hpp>

#include <boost/hana/assert.hpp>
#include <boost/hana/tuple.hpp>

#include <laws/iterable.hpp>

#include <cstddef>
#include <utility>
using namespace boost::hana;


using T = int;
using U = long long;

int main() {
    //////////////////////////////////////////////////////////////////////////
    // Setup for the laws below
    //////////////////////////////////////////////////////////////////////////
    auto sequences = make<Tuple>(
        std::integer_sequence<T>{},
        std::integer_sequence<U>{},

        std::integer_sequence<T, 0>{},
        std::integer_sequence<U, 0>{},

        std::integer_sequence<T, 0, 1>{},
        std::integer_sequence<U, 0, 1>{},

        std::integer_sequence<T, 1, 0, 2>{},
        std::integer_sequence<U, 1, 0, 2>{}
    );

    //////////////////////////////////////////////////////////////////////////
    // Iterable
    //////////////////////////////////////////////////////////////////////////
    // head
    {
        BOOST_HANA_CONSTANT_CHECK(equal(
            head(std::index_sequence<0>{}),
            std::integral_constant<std::size_t, 0>{}
        ));
        BOOST_HANA_CONSTANT_CHECK(equal(
            head(std::index_sequence<0, 1>{}),
            std::integral_constant<std::size_t, 0>{}
        ));
    }

    // is_empty
    {
        BOOST_HANA_CONSTANT_CHECK(is_empty(std::index_sequence<>{}));
        BOOST_HANA_CONSTANT_CHECK(not_(is_empty(std::index_sequence<0>{})));
        BOOST_HANA_CONSTANT_CHECK(not_(is_empty(std::index_sequence<1>{})));
    }

    // tail
    {
        BOOST_HANA_CONSTANT_CHECK(equal(
            tail(std::index_sequence<0>{}),
            std::index_sequence<>{}
        ));
        BOOST_HANA_CONSTANT_CHECK(equal(
            tail(std::index_sequence<0, 1>{}),
            std::index_sequence<1>{}
        ));
        BOOST_HANA_CONSTANT_CHECK(equal(
            tail(std::index_sequence<0, 1, 2>{}),
            std::index_sequence<1, 2>{}
        ));
    }

    // laws
    test::TestIterable<ext::std::IntegerSequence>{sequences};
}