tuple_utility.hpp

Go to the documentation of this file.

// -----------------------------------------------------------------------------------------------------
// Copyright (c) 2006-2019, Knut Reinert & Freie Universität Berlin
// Copyright (c) 2016-2019, Knut Reinert & MPI für molekulare Genetik
// This file may be used, modified and/or redistributed under the terms of the 3-clause BSD-License
// shipped with this file and also available at: https://github.com/seqan/seqan3/blob/master/LICENSE.md
// -----------------------------------------------------------------------------------------------------

#pragma once

#include <meta/meta.hpp>

#include <utility>

#include <seqan3/core/concept/tuple.hpp>
#include <seqan3/core/pod_tuple.hpp>
#include <seqan3/core/type_list.hpp>
#include <seqan3/core/type_traits/basic.hpp>
#include <seqan3/core/type_traits/template_inspection.hpp>

namespace seqan3::detail
{

template <size_t beg,
          template <typename ...> typename tuple_t,
          size_t ... Is,
          typename ...ts>
    requires TupleLike<tuple_t<ts...>> && TupleLike<tuple_t<>>
constexpr auto tuple_split(tuple_t<ts...> const & t, std::index_sequence<Is...> const & SEQAN3_DOXYGEN_ONLY(idx))
{
    return tuple_t<std::tuple_element_t<beg + Is, tuple_t<ts...>>...>{std::get<beg + Is>(t)...};
}

template <size_t beg,
          template <typename ...> typename tuple_t,
          size_t ... Is,
          typename ...ts>
    requires TupleLike<tuple_t<ts...>> && TupleLike<tuple_t<>>
constexpr auto tuple_split(tuple_t<ts...> && t, std::index_sequence<Is...> const & SEQAN3_DOXYGEN_ONLY(idx))
{
    return tuple_t<std::tuple_element_t<beg + Is, tuple_t<ts...>>...>{std::move(std::get<beg + Is>(t))...};
}
} // namespace seqan3::detail

namespace seqan3
{
template <size_t pivot_c, template <typename ...> typename tuple_t, typename ... ts>
    requires TupleLike<tuple_t<ts...>>
constexpr auto tuple_split(tuple_t<ts...> const & t)
{
    static_assert(pivot_c <= sizeof...(ts));

    return tuple_t{detail::tuple_split<0>(t, std::make_index_sequence<pivot_c>{}),
                   detail::tuple_split<pivot_c>(t, std::make_index_sequence<sizeof...(ts) - pivot_c>{})};
}

template <size_t pivot_c, template <typename ...> typename tuple_t, typename ... ts>
    requires TupleLike<tuple_t<ts...>>
constexpr auto tuple_split(tuple_t<ts...> && t)
{
    static_assert(pivot_c <= sizeof...(ts));

    return tuple_t{detail::tuple_split<0>(std::move(t), std::make_index_sequence<pivot_c>{}),
                   detail::tuple_split<pivot_c>(std::move(t), std::make_index_sequence<sizeof...(ts) - pivot_c>{})};
}

template <typename pivot_t, TupleLike tuple_t>
constexpr auto tuple_split(tuple_t && t)
{
    constexpr size_t pivot_c = meta::find_index<detail::tuple_type_list_t<remove_cvref_t<tuple_t>>, pivot_t>::value;

    static_assert(pivot_c <= std::tuple_size_v<remove_cvref_t<tuple_t>>);

    return tuple_split<pivot_c>(std::forward<tuple_t>(t));
}

template <TupleLike tuple_t>
constexpr auto tuple_pop_front(tuple_t && t)
{
    static_assert(std::tuple_size_v<remove_cvref_t<tuple_t>> > 0);

    return std::get<1>(tuple_split<1>(std::forward<tuple_t>(t)));
}

} // namespace seqan3