iterator.hpp

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// -----------------------------------------------------------------------------------------------------
// Copyright (c) 2006-2020, Knut Reinert & Freie Universität Berlin
// Copyright (c) 2016-2020, 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 <iterator>
#include <type_traits>
 
#include <seqan3/core/platform.hpp>
#include <seqan3/core/type_traits/pre.hpp>
#include <seqan3/std/iterator>
 
namespace seqan3
{
 
// ----------------------------------------------------------------------------
// value_type
// ----------------------------------------------------------------------------
 
#ifdef SEQAN3_DEPRECATED_310
namespace detail
{
template <std::input_iterator it_t>
struct value_type<it_t>
{
    using type = std::iter_value_t<it_t>;
};
} // namespace seqan3::detail
#endif // SEQAN3_DEPRECATED_310
 
// see specialisation for ranges in core/type_traits/range.hpp
 
// ----------------------------------------------------------------------------
// reference
// ----------------------------------------------------------------------------
 
#ifdef SEQAN3_DEPRECATED_310
namespace detail
{
template <std::input_iterator it_t>
struct reference<it_t>
{
    using type = std::iter_reference_t<it_t>;
};
} // namespace seqan3::detail
#endif // SEQAN3_DEPRECATED_310
 
// see specialisation for ranges in core/type_traits/range.hpp
 
// ----------------------------------------------------------------------------
// rvalue_reference
// ----------------------------------------------------------------------------
 
#ifdef SEQAN3_DEPRECATED_310
namespace detail
{
template <std::input_iterator it_t>
struct rvalue_reference<it_t>
{
    using type = std::iter_rvalue_reference_t<it_t>;
};
} // namespace seqan3::detail
#endif // SEQAN3_DEPRECATED_310
 
// see specialisation for ranges in core/type_traits/range.hpp
 
// ----------------------------------------------------------------------------
// const_reference
// ----------------------------------------------------------------------------
 
// only defined for ranges
 
// ----------------------------------------------------------------------------
// difference_type
// ----------------------------------------------------------------------------
 
#ifdef SEQAN3_DEPRECATED_310
namespace detail
{
template <std::weakly_incrementable it_t>
struct difference_type<it_t>
{
    using type = std::iter_difference_t<it_t>;
};
} // namespace seqan3::detail
#endif // SEQAN3_DEPRECATED_310
 
// see specialisation for ranges in core/type_traits/range.hpp
 
// ----------------------------------------------------------------------------
// size_type
// ----------------------------------------------------------------------------
 
#ifdef SEQAN3_DEPRECATED_310
namespace detail
{
template <std::weakly_incrementable it_t>
struct size_type<it_t>
{
    using type = std::make_unsigned_t<std::iter_difference_t<it_t>>;
};
} // namespace seqan3::detail
#endif // SEQAN3_DEPRECATED_310
 
// see specialisation for ranges in core/type_traits/range.hpp
 
} // namespace seqan3
 
namespace seqan3::detail
{
#if SEQAN3_WORKAROUND_GCC_96070
template <typename it_t>
struct iterator_category_tag
{
    using type = void;
};
 
template <typename it_t>
    requires requires { typename std::iterator_traits<it_t>::iterator_category; }
struct iterator_category_tag<it_t>
{
    using type = typename std::iterator_traits<it_t>::iterator_category;
};
 
template <typename it_t>
using iterator_category_tag_t = typename iterator_category_tag<it_t>::type;
#else // ^^^ workaround / no workaround vvv
// TODO: Change the description / the definition of iterator_category_tag_t depending on how the standard resolves this
// https://github.com/seqan/product_backlog/issues/151
 
template <typename it_t>
    requires requires { typename std::iterator_traits<it_t>::iterator_category; }
using iterator_category_tag_t = typename std::iterator_traits<it_t>::iterator_category;
#endif // SEQAN3_WORKAROUND_GCC_96070
 
template <typename it_t>
    requires std::input_or_output_iterator<it_t>
using iterator_concept_tag_t =
    std::conditional_t<
        std::contiguous_iterator<it_t>,
        std::contiguous_iterator_tag,
        std::conditional_t<
            std::random_access_iterator<it_t>,
            std::random_access_iterator_tag,
            std::conditional_t<
                std::bidirectional_iterator<it_t>,
                std::bidirectional_iterator_tag,
                std::conditional_t<
                    std::forward_iterator<it_t>,
                    std::forward_iterator_tag,
                    std::conditional_t<
                        std::input_iterator<it_t>,
                        std::input_iterator_tag,
                        std::output_iterator_tag>>>>>;
 
} // namespace seqan3::detail
 
namespace seqan3::detail
{
// ----------------------------------------------------------------------------
// iter_pointer
// ----------------------------------------------------------------------------
 
template <typename it_t>
struct iter_pointer
{
    using type = void;
};
 
template <typename it_t>
    requires requires { typename std::iterator_traits<it_t>::pointer; }
struct iter_pointer<it_t>
{
    using type = typename std::iterator_traits<it_t>::pointer;
};
 
template <typename it_t>
using iter_pointer_t = typename iter_pointer<it_t>::type;
 
} // namespace seqan3::detail