928 lines
33 KiB
C++
928 lines
33 KiB
C++
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// Copyright (C) 2019 T. Zachary Laine
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//
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// Distributed under the Boost Software License, Version 1.0. (See
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// accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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#ifndef BOOST_STL_INTERFACES_ITERATOR_INTERFACE_HPP
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#define BOOST_STL_INTERFACES_ITERATOR_INTERFACE_HPP
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#include <boost/stl_interfaces/fwd.hpp>
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#include <utility>
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#include <type_traits>
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#if defined(__cpp_lib_three_way_comparison)
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#include <compare>
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#endif
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namespace boost { namespace stl_interfaces {
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/** A type for granting access to the private members of an iterator
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derived from `iterator_interface`. */
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struct access
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{
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#ifndef BOOST_STL_INTERFACES_DOXYGEN
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template<typename D>
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static constexpr auto base(D & d) noexcept
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-> decltype(d.base_reference())
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{
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return d.base_reference();
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}
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template<typename D>
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static constexpr auto base(D const & d) noexcept
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-> decltype(d.base_reference())
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{
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return d.base_reference();
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}
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#endif
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};
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/** The return type of `operator->()` in a proxy iterator.
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This template is used as the default `Pointer` template parameter in
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the `proxy_iterator_interface` template alias. Note that the use of
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this template implies a copy or move of the underlying object of type
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`T`. */
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template<typename T>
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#if defined(BOOST_STL_INTERFACES_DOXYGEN) || BOOST_STL_INTERFACES_USE_CONCEPTS
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// clang-format off
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requires std::is_object_v<T>
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#endif
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struct proxy_arrow_result
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// clang-format on
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{
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constexpr proxy_arrow_result(T const & value) noexcept(
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noexcept(T(value))) :
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value_(value)
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{}
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constexpr proxy_arrow_result(T && value) noexcept(
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noexcept(T(std::move(value)))) :
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value_(std::move(value))
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{}
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constexpr T const * operator->() const noexcept { return &value_; }
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constexpr T * operator->() noexcept { return &value_; }
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private:
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T value_;
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};
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namespace detail {
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template<typename Pointer, typename T>
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auto make_pointer(
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T && value,
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std::enable_if_t<std::is_pointer<Pointer>::value, int> = 0)
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-> decltype(std::addressof(value))
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{
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return std::addressof(value);
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}
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template<typename Pointer, typename T>
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auto make_pointer(
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T && value,
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std::enable_if_t<!std::is_pointer<Pointer>::value, int> = 0)
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{
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return Pointer(std::forward<T>(value));
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}
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template<typename IteratorConcept>
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struct concept_category
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{
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using type = IteratorConcept;
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};
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template<typename IteratorConcept>
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using concept_category_t =
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typename concept_category<IteratorConcept>::type;
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template<typename Pointer, typename IteratorConcept>
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struct pointer
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{
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using type = Pointer;
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};
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template<typename Pointer>
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struct pointer<Pointer, std::output_iterator_tag>
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{
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using type = void;
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};
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template<typename Pointer, typename IteratorConcept>
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using pointer_t = typename pointer<Pointer, IteratorConcept>::type;
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template<typename T, typename U>
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using interoperable = std::integral_constant<
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bool,
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(std::is_convertible<T, U>::value ||
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std::is_convertible<U, T>::value)>;
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template<typename T, typename U>
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using common_t =
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std::conditional_t<std::is_convertible<T, U>::value, U, T>;
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template<typename T>
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using use_base = decltype(access::base(std::declval<T &>()));
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template<typename... T>
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using void_t = void;
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template<
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typename AlwaysVoid,
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template<class...> class Template,
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typename... Args>
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struct detector : std::false_type
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{
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};
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template<template<class...> class Template, typename... Args>
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struct detector<void_t<Template<Args...>>, Template, Args...>
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: std::true_type
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{
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};
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template<
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typename T,
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typename U,
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bool UseBase = detector<void, use_base, T>::value>
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struct common_eq
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{
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static constexpr auto call(T lhs, U rhs)
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{
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return static_cast<common_t<T, U>>(lhs).derived() ==
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static_cast<common_t<T, U>>(rhs).derived();
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}
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};
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template<typename T, typename U>
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struct common_eq<T, U, true>
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{
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static constexpr auto call(T lhs, U rhs)
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{
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return access::base(lhs) == access::base(rhs);
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}
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};
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template<typename T, typename U>
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constexpr auto common_diff(T lhs, U rhs) noexcept(noexcept(
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static_cast<common_t<T, U>>(lhs) -
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static_cast<common_t<T, U>>(rhs)))
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-> decltype(
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static_cast<common_t<T, U>>(lhs) -
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static_cast<common_t<T, U>>(rhs))
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{
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return static_cast<common_t<T, U>>(lhs) -
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static_cast<common_t<T, U>>(rhs);
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}
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}
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}}
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namespace boost { namespace stl_interfaces { BOOST_STL_INTERFACES_NAMESPACE_V1 {
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/** A CRTP template that one may derive from to make defining iterators
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easier.
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The template parameter `D` for `iterator_interface` may be an
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incomplete type. Before any member of the resulting specialization of
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`iterator_interface` other than special member functions is
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referenced, `D` shall be complete, and model
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`std::derived_from<iterator_interface<D>>`. */
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template<
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typename Derived,
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typename IteratorConcept,
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typename ValueType,
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typename Reference = ValueType &,
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typename Pointer = ValueType *,
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typename DifferenceType = std::ptrdiff_t
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#ifndef BOOST_STL_INTERFACES_DOXYGEN
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,
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typename E = std::enable_if_t<
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std::is_class<Derived>::value &&
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std::is_same<Derived, std::remove_cv_t<Derived>>::value>
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#endif
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>
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struct iterator_interface;
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namespace v1_dtl {
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template<typename Iterator, typename = void>
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struct ra_iter : std::false_type
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{
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};
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template<typename Iterator>
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struct ra_iter<Iterator, void_t<typename Iterator::iterator_concept>>
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: std::integral_constant<
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bool,
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std::is_base_of<
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std::random_access_iterator_tag,
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typename Iterator::iterator_concept>::value>
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{
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};
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template<typename Iterator, typename DifferenceType, typename = void>
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struct plus_eq : std::false_type
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{
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};
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template<typename Iterator, typename DifferenceType>
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struct plus_eq<
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Iterator,
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DifferenceType,
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void_t<decltype(
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std::declval<Iterator &>() += std::declval<DifferenceType>())>>
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: std::true_type
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{
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};
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template<
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typename D,
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typename IteratorConcept,
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typename ValueType,
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typename Reference,
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typename Pointer,
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typename DifferenceType>
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void derived_iterator(iterator_interface<
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D,
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IteratorConcept,
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ValueType,
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Reference,
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Pointer,
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DifferenceType> const &);
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}
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template<
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typename Derived,
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typename IteratorConcept,
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typename ValueType,
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typename Reference,
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typename Pointer,
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typename DifferenceType
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#ifndef BOOST_STL_INTERFACES_DOXYGEN
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,
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typename E
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#endif
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>
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struct iterator_interface
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{
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#ifndef BOOST_STL_INTERFACES_DOXYGEN
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private:
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constexpr Derived & derived() noexcept
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{
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return static_cast<Derived &>(*this);
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}
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constexpr Derived const & derived() const noexcept
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{
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return static_cast<Derived const &>(*this);
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}
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template<typename T, typename U, bool UseBase>
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friend struct detail::common_eq;
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#endif
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public:
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using iterator_concept = IteratorConcept;
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using iterator_category = detail::concept_category_t<iterator_concept>;
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using value_type = std::remove_const_t<ValueType>;
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using reference = Reference;
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using pointer = detail::pointer_t<Pointer, iterator_concept>;
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using difference_type = DifferenceType;
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template<typename D = Derived>
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constexpr auto operator*() const
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noexcept(noexcept(*access::base(std::declval<D const &>())))
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-> decltype(*access::base(std::declval<D const &>()))
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{
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return *access::base(derived());
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}
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template<typename D = Derived>
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constexpr auto operator-> () const noexcept(
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noexcept(detail::make_pointer<pointer>(*std::declval<D const &>())))
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-> decltype(
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detail::make_pointer<pointer>(*std::declval<D const &>()))
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{
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return detail::make_pointer<pointer>(*derived());
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}
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template<typename D = Derived>
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constexpr auto operator[](difference_type i) const noexcept(noexcept(
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D(std::declval<D const &>()),
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std::declval<D &>() += i,
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*std::declval<D &>()))
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-> decltype(std::declval<D &>() += i, *std::declval<D &>())
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{
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D retval = derived();
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retval += i;
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return *retval;
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}
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template<
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typename D = Derived,
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typename Enable =
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std::enable_if_t<!v1_dtl::plus_eq<D, difference_type>::value>>
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constexpr auto
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operator++() noexcept(noexcept(++access::base(std::declval<D &>())))
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-> decltype(
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++access::base(std::declval<D &>()), std::declval<D &>())
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{
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++access::base(derived());
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return derived();
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}
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template<typename D = Derived>
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constexpr auto operator++() noexcept(
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noexcept(std::declval<D &>() += difference_type(1)))
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-> decltype(
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std::declval<D &>() += difference_type(1), std::declval<D &>())
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{
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derived() += difference_type(1);
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return derived();
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}
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template<typename D = Derived>
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constexpr auto operator++(int)noexcept(
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noexcept(D(std::declval<D &>()), ++std::declval<D &>()))
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-> std::remove_reference_t<decltype(
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D(std::declval<D &>()),
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++std::declval<D &>(),
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std::declval<D &>())>
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{
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D retval = derived();
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++derived();
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return retval;
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}
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template<typename D = Derived>
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constexpr auto operator+=(difference_type n) noexcept(
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noexcept(access::base(std::declval<D &>()) += n))
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-> decltype(
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access::base(std::declval<D &>()) += n, std::declval<D &>())
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{
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access::base(derived()) += n;
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return derived();
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}
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template<typename D = Derived>
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constexpr auto operator+(difference_type i) const
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noexcept(noexcept(D(std::declval<D &>()), std::declval<D &>() += i))
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-> std::remove_reference_t<decltype(
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D(std::declval<D &>()),
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std::declval<D &>() += i,
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std::declval<D &>())>
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{
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D retval = derived();
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retval += i;
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return retval;
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}
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friend BOOST_STL_INTERFACES_HIDDEN_FRIEND_CONSTEXPR Derived
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operator+(difference_type i, Derived it) noexcept
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{
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return it + i;
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}
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template<
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typename D = Derived,
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typename Enable =
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std::enable_if_t<!v1_dtl::plus_eq<D, difference_type>::value>>
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constexpr auto
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operator--() noexcept(noexcept(--access::base(std::declval<D &>())))
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-> decltype(--access::base(std::declval<D &>()), std::declval<D &>())
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{
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--access::base(derived());
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return derived();
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}
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template<typename D = Derived>
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constexpr auto operator--() noexcept(noexcept(
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D(std::declval<D &>()), std::declval<D &>() += -difference_type(1)))
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-> decltype(
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std::declval<D &>() += -difference_type(1), std::declval<D &>())
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{
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derived() += -difference_type(1);
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return derived();
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}
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template<typename D = Derived>
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constexpr auto operator--(int)noexcept(
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noexcept(D(std::declval<D &>()), --std::declval<D &>()))
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-> std::remove_reference_t<decltype(
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D(std::declval<D &>()),
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--std::declval<D &>(),
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std::declval<D &>())>
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{
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D retval = derived();
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--derived();
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return retval;
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}
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template<typename D = Derived>
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constexpr D & operator-=(difference_type i) noexcept
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{
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derived() += -i;
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return derived();
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}
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template<typename D = Derived>
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constexpr auto operator-(D other) const noexcept(noexcept(
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access::base(std::declval<D const &>()) - access::base(other)))
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-> decltype(
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access::base(std::declval<D const &>()) - access::base(other))
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{
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return access::base(derived()) - access::base(other);
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}
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friend BOOST_STL_INTERFACES_HIDDEN_FRIEND_CONSTEXPR Derived
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operator-(Derived it, difference_type i) noexcept
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{
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Derived retval = it;
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retval += -i;
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return retval;
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}
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};
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/** Implementation of `operator==()`, implemented in terms of the iterator
|
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|
underlying IteratorInterface, for all iterators derived from
|
||
|
`iterator_interface`, except those with an iterator category derived
|
||
|
from `std::random_access_iterator_tag`. */
|
||
|
template<
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typename IteratorInterface1,
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typename IteratorInterface2,
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||
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typename Enable =
|
||
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std::enable_if_t<!v1_dtl::ra_iter<IteratorInterface1>::value>>
|
||
|
constexpr auto
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||
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operator==(IteratorInterface1 lhs, IteratorInterface2 rhs) noexcept
|
||
|
-> decltype(
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||
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access::base(std::declval<IteratorInterface1 &>()) ==
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||
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access::base(std::declval<IteratorInterface2 &>()))
|
||
|
{
|
||
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return access::base(lhs) == access::base(rhs);
|
||
|
}
|
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||
|
/** Implementation of `operator==()` for all iterators derived from
|
||
|
`iterator_interface` that have an iterator category derived from
|
||
|
`std::random_access_iterator_tag`. */
|
||
|
template<
|
||
|
typename IteratorInterface1,
|
||
|
typename IteratorInterface2,
|
||
|
typename Enable =
|
||
|
std::enable_if_t<v1_dtl::ra_iter<IteratorInterface1>::value>>
|
||
|
constexpr auto
|
||
|
operator==(IteratorInterface1 lhs, IteratorInterface2 rhs) noexcept(
|
||
|
noexcept(detail::common_diff(lhs, rhs)))
|
||
|
-> decltype(
|
||
|
v1_dtl::derived_iterator(lhs), detail::common_diff(lhs, rhs) == 0)
|
||
|
{
|
||
|
return detail::common_diff(lhs, rhs) == 0;
|
||
|
}
|
||
|
|
||
|
/** Implementation of `operator!=()` for all iterators derived from
|
||
|
`iterator_interface`. */
|
||
|
template<typename IteratorInterface1, typename IteratorInterface2>
|
||
|
constexpr auto operator!=(
|
||
|
IteratorInterface1 lhs,
|
||
|
IteratorInterface2 rhs) noexcept(noexcept(!(lhs == rhs)))
|
||
|
-> decltype(v1_dtl::derived_iterator(lhs), !(lhs == rhs))
|
||
|
{
|
||
|
return !(lhs == rhs);
|
||
|
}
|
||
|
|
||
|
/** Implementation of `operator<()` for all iterators derived from
|
||
|
`iterator_interface` that have an iterator category derived from
|
||
|
`std::random_access_iterator_tag`. */
|
||
|
template<typename IteratorInterface1, typename IteratorInterface2>
|
||
|
constexpr auto
|
||
|
operator<(IteratorInterface1 lhs, IteratorInterface2 rhs) noexcept(
|
||
|
noexcept(detail::common_diff(lhs, rhs)))
|
||
|
-> decltype(
|
||
|
v1_dtl::derived_iterator(lhs), detail::common_diff(lhs, rhs) < 0)
|
||
|
{
|
||
|
return detail::common_diff(lhs, rhs) < 0;
|
||
|
}
|
||
|
|
||
|
/** Implementation of `operator<=()` for all iterators derived from
|
||
|
`iterator_interface` that have an iterator category derived from
|
||
|
`std::random_access_iterator_tag`. */
|
||
|
template<typename IteratorInterface1, typename IteratorInterface2>
|
||
|
constexpr auto
|
||
|
operator<=(IteratorInterface1 lhs, IteratorInterface2 rhs) noexcept(
|
||
|
noexcept(detail::common_diff(lhs, rhs)))
|
||
|
-> decltype(
|
||
|
v1_dtl::derived_iterator(lhs), detail::common_diff(lhs, rhs) <= 0)
|
||
|
{
|
||
|
return detail::common_diff(lhs, rhs) <= 0;
|
||
|
}
|
||
|
|
||
|
/** Implementation of `operator>()` for all iterators derived from
|
||
|
`iterator_interface` that have an iterator category derived from
|
||
|
`std::random_access_iterator_tag`. */
|
||
|
template<typename IteratorInterface1, typename IteratorInterface2>
|
||
|
constexpr auto
|
||
|
operator>(IteratorInterface1 lhs, IteratorInterface2 rhs) noexcept(
|
||
|
noexcept(detail::common_diff(lhs, rhs)))
|
||
|
-> decltype(
|
||
|
v1_dtl::derived_iterator(lhs), detail::common_diff(lhs, rhs) > 0)
|
||
|
{
|
||
|
return detail::common_diff(lhs, rhs) > 0;
|
||
|
}
|
||
|
|
||
|
/** Implementation of `operator>=()` for all iterators derived from
|
||
|
`iterator_interface` that have an iterator category derived from
|
||
|
`std::random_access_iterator_tag`. */
|
||
|
template<typename IteratorInterface1, typename IteratorInterface2>
|
||
|
constexpr auto
|
||
|
operator>=(IteratorInterface1 lhs, IteratorInterface2 rhs) noexcept(
|
||
|
noexcept(detail::common_diff(lhs, rhs)))
|
||
|
-> decltype(
|
||
|
v1_dtl::derived_iterator(lhs), detail::common_diff(lhs, rhs) >= 0)
|
||
|
{
|
||
|
return detail::common_diff(lhs, rhs) >= 0;
|
||
|
}
|
||
|
|
||
|
|
||
|
/** A template alias useful for defining proxy iterators. \see
|
||
|
`iterator_interface`. */
|
||
|
template<
|
||
|
typename Derived,
|
||
|
typename IteratorConcept,
|
||
|
typename ValueType,
|
||
|
typename Reference = ValueType,
|
||
|
typename DifferenceType = std::ptrdiff_t>
|
||
|
using proxy_iterator_interface = iterator_interface<
|
||
|
Derived,
|
||
|
IteratorConcept,
|
||
|
ValueType,
|
||
|
Reference,
|
||
|
proxy_arrow_result<Reference>,
|
||
|
DifferenceType>;
|
||
|
|
||
|
}}}
|
||
|
|
||
|
#if defined(BOOST_STL_INTERFACES_DOXYGEN) || BOOST_STL_INTERFACES_USE_CONCEPTS
|
||
|
|
||
|
namespace boost { namespace stl_interfaces { BOOST_STL_INTERFACES_NAMESPACE_V2 {
|
||
|
|
||
|
namespace v2_dtl {
|
||
|
template<typename Iterator>
|
||
|
struct iter_concept;
|
||
|
|
||
|
template<typename Iterator>
|
||
|
requires requires
|
||
|
{
|
||
|
typename std::iterator_traits<Iterator>::iterator_concept;
|
||
|
}
|
||
|
struct iter_concept<Iterator>
|
||
|
{
|
||
|
using type =
|
||
|
typename std::iterator_traits<Iterator>::iterator_concept;
|
||
|
};
|
||
|
|
||
|
template<typename Iterator>
|
||
|
requires(
|
||
|
!requires {
|
||
|
typename std::iterator_traits<Iterator>::iterator_concept;
|
||
|
} &&
|
||
|
requires {
|
||
|
typename std::iterator_traits<Iterator>::iterator_category;
|
||
|
})
|
||
|
struct iter_concept<Iterator>
|
||
|
{
|
||
|
using type =
|
||
|
typename std::iterator_traits<Iterator>::iterator_category;
|
||
|
};
|
||
|
|
||
|
template<typename Iterator>
|
||
|
requires(
|
||
|
!requires {
|
||
|
typename std::iterator_traits<Iterator>::iterator_concept;
|
||
|
} &&
|
||
|
!requires {
|
||
|
typename std::iterator_traits<Iterator>::iterator_category;
|
||
|
})
|
||
|
struct iter_concept<Iterator>
|
||
|
{
|
||
|
using type = std::random_access_iterator_tag;
|
||
|
};
|
||
|
|
||
|
template<typename Iterator>
|
||
|
struct iter_concept
|
||
|
{};
|
||
|
|
||
|
template<typename Iterator>
|
||
|
using iter_concept_t = typename iter_concept<Iterator>::type;
|
||
|
|
||
|
template<typename D, typename DifferenceType>
|
||
|
// clang-format off
|
||
|
concept plus_eq = requires (D d) { d += DifferenceType(1); };
|
||
|
// clang-format on
|
||
|
|
||
|
template<typename D>
|
||
|
// clang-format off
|
||
|
concept base_3way =
|
||
|
requires (D d) { access::base(d) <=> access::base(d); };
|
||
|
// clang-format on
|
||
|
|
||
|
template<typename D1, typename D2 = D1>
|
||
|
// clang-format off
|
||
|
concept base_eq =
|
||
|
requires (D1 d1, D2 d2) { access::base(d1) == access::base(d2); };
|
||
|
// clang-format on
|
||
|
|
||
|
template<typename D>
|
||
|
// clang-format off
|
||
|
concept sub = requires (D d) { d - d; };
|
||
|
// clang-format on
|
||
|
}
|
||
|
|
||
|
// clang-format off
|
||
|
|
||
|
/** A CRTP template that one may derive from to make defining iterators
|
||
|
easier.
|
||
|
|
||
|
The template parameter `D` for `iterator_interface` may be an
|
||
|
incomplete type. Before any member of the resulting specialization of
|
||
|
`iterator_interface` other than special member functions is
|
||
|
referenced, `D` shall be complete, and model
|
||
|
`std::derived_from<iterator_interface<D>>`. */
|
||
|
template<
|
||
|
typename D,
|
||
|
typename IteratorConcept,
|
||
|
typename ValueType,
|
||
|
typename Reference = ValueType &,
|
||
|
typename Pointer = ValueType *,
|
||
|
typename DifferenceType = std::ptrdiff_t>
|
||
|
requires std::is_class_v<D> && std::same_as<D, std::remove_cv_t<D>>
|
||
|
struct iterator_interface
|
||
|
{
|
||
|
private:
|
||
|
constexpr D& derived() noexcept {
|
||
|
return static_cast<D&>(*this);
|
||
|
}
|
||
|
constexpr const D& derived() const noexcept {
|
||
|
return static_cast<const D&>(*this);
|
||
|
}
|
||
|
|
||
|
public:
|
||
|
using iterator_concept = IteratorConcept;
|
||
|
using iterator_category = detail::concept_category_t<iterator_concept>;
|
||
|
using value_type = std::remove_const_t<ValueType>;
|
||
|
using reference = Reference;
|
||
|
using pointer = detail::pointer_t<Pointer, iterator_concept>;
|
||
|
using difference_type = DifferenceType;
|
||
|
|
||
|
constexpr decltype(auto) operator*()
|
||
|
requires requires (D d) { *access::base(d); } {
|
||
|
return *access::base(derived());
|
||
|
}
|
||
|
constexpr decltype(auto) operator*() const
|
||
|
requires requires (D const d) { *access::base(d); } {
|
||
|
return *access::base(derived());
|
||
|
}
|
||
|
|
||
|
constexpr auto operator->()
|
||
|
requires requires (D d) { *d; } {
|
||
|
return detail::make_pointer<pointer>(*derived());
|
||
|
}
|
||
|
constexpr auto operator->() const
|
||
|
requires requires (D const d) { *d; } {
|
||
|
return detail::make_pointer<pointer>(*derived());
|
||
|
}
|
||
|
|
||
|
constexpr decltype(auto) operator[](difference_type n) const
|
||
|
requires requires (D const d) { d + n; } {
|
||
|
D retval = derived();
|
||
|
retval += n;
|
||
|
return *retval;
|
||
|
}
|
||
|
|
||
|
constexpr decltype(auto) operator++()
|
||
|
requires requires (D d) { ++access::base(d); } &&
|
||
|
(!v2_dtl::plus_eq<D, difference_type>) {
|
||
|
++access::base(derived());
|
||
|
return derived();
|
||
|
}
|
||
|
constexpr decltype(auto) operator++()
|
||
|
requires requires (D d) { d += difference_type(1); } {
|
||
|
return derived() += difference_type(1);
|
||
|
}
|
||
|
constexpr auto operator++(int) requires requires (D d) { ++d; } {
|
||
|
D retval = derived();
|
||
|
++derived();
|
||
|
return retval;
|
||
|
}
|
||
|
constexpr decltype(auto) operator+=(difference_type n)
|
||
|
requires requires (D d) { access::base(d) += n; } {
|
||
|
access::base(derived()) += n;
|
||
|
return derived();
|
||
|
}
|
||
|
friend constexpr auto operator+(D it, difference_type n)
|
||
|
requires requires { it += n; } {
|
||
|
return it += n;
|
||
|
}
|
||
|
friend constexpr auto operator+(difference_type n, D it)
|
||
|
requires requires { it += n; } {
|
||
|
return it += n;
|
||
|
}
|
||
|
|
||
|
constexpr decltype(auto) operator--()
|
||
|
requires requires (D d) { --access::base(d); } &&
|
||
|
(!v2_dtl::plus_eq<D, difference_type>) {
|
||
|
--access::base(derived());
|
||
|
return derived();
|
||
|
}
|
||
|
constexpr decltype(auto) operator--()
|
||
|
requires requires (D d) { d += -difference_type(1); } {
|
||
|
return derived() += -difference_type(1);
|
||
|
}
|
||
|
constexpr auto operator--(int) requires requires (D d) { --d; } {
|
||
|
D retval = derived();
|
||
|
--derived();
|
||
|
return retval;
|
||
|
}
|
||
|
constexpr decltype(auto) operator-=(difference_type n)
|
||
|
requires requires (D d) { d += -n; } {
|
||
|
return derived() += -n;
|
||
|
}
|
||
|
friend constexpr auto operator-(D lhs, D rhs)
|
||
|
requires requires { access::base(lhs) - access::base(rhs); } {
|
||
|
return access::base(lhs) - access::base(rhs);
|
||
|
}
|
||
|
friend constexpr auto operator-(D it, difference_type n)
|
||
|
requires requires { it += -n; } {
|
||
|
return it += -n;
|
||
|
}
|
||
|
|
||
|
#if 0 // TODO: This appears to work, but as of this writing (and using GCC
|
||
|
// 10), op<=> is not yet being used to evaluate op==, op<, etc.
|
||
|
friend constexpr std::strong_ordering operator<=>(D lhs, D rhs)
|
||
|
requires v2_dtl::base_3way<D> || v2_dtl::sub<D> {
|
||
|
if constexpr (requires { access::base(lhs) <=> access::base(rhs); }) {
|
||
|
return access::base(lhs) <=> access::base(rhs);
|
||
|
} else {
|
||
|
auto delta = lhs - rhs;
|
||
|
if (delta < 0)
|
||
|
return std::strong_ordering::less;
|
||
|
if (0 < delta)
|
||
|
return std::strong_ordering::greater;
|
||
|
return std::strong_ordering::equal;
|
||
|
}
|
||
|
}
|
||
|
#else
|
||
|
friend constexpr bool operator<(D lhs, D rhs)
|
||
|
requires std::equality_comparable<D> {
|
||
|
return (lhs - rhs) < typename D::difference_type(0);
|
||
|
}
|
||
|
friend constexpr bool operator<=(D lhs, D rhs)
|
||
|
requires std::equality_comparable<D> {
|
||
|
return (lhs - rhs) <= typename D::difference_type(0);
|
||
|
}
|
||
|
friend constexpr bool operator>(D lhs, D rhs)
|
||
|
requires std::equality_comparable<D> {
|
||
|
return (lhs - rhs) > typename D::difference_type(0);
|
||
|
}
|
||
|
friend constexpr bool operator>=(D lhs, D rhs)
|
||
|
requires std::equality_comparable<D> {
|
||
|
return (lhs - rhs) >= typename D::difference_type(0);
|
||
|
}
|
||
|
#endif
|
||
|
};
|
||
|
|
||
|
namespace v2_dtl {
|
||
|
template<
|
||
|
typename D,
|
||
|
typename IteratorConcept,
|
||
|
typename ValueType,
|
||
|
typename Reference,
|
||
|
typename Pointer,
|
||
|
typename DifferenceType>
|
||
|
void derived_iterator(v2::iterator_interface<
|
||
|
D,
|
||
|
IteratorConcept,
|
||
|
ValueType,
|
||
|
Reference,
|
||
|
Pointer,
|
||
|
DifferenceType> const &);
|
||
|
|
||
|
template<typename D>
|
||
|
concept derived_iter = requires (D d) { v2_dtl::derived_iterator(d); };
|
||
|
}
|
||
|
|
||
|
template<typename D1, typename D2>
|
||
|
constexpr bool operator==(D1 lhs, D2 rhs)
|
||
|
requires v2_dtl::derived_iter<D1> && v2_dtl::derived_iter<D2> &&
|
||
|
detail::interoperable<D1, D2>::value &&
|
||
|
(v2_dtl::base_eq<D1, D2> || v2_dtl::sub<D1>) {
|
||
|
if constexpr (v2_dtl::base_eq<D1, D2>) {
|
||
|
return (access::base(lhs) == access::base(rhs));
|
||
|
} else if constexpr (v2_dtl::sub<D1>) {
|
||
|
return (lhs - rhs) == typename D1::difference_type(0);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
template<typename D1, typename D2>
|
||
|
constexpr auto operator!=(D1 lhs, D2 rhs) -> decltype(!(lhs == rhs))
|
||
|
requires v2_dtl::derived_iter<D1> && v2_dtl::derived_iter<D2>
|
||
|
{ return !(lhs == rhs); }
|
||
|
|
||
|
// clang-format on
|
||
|
|
||
|
|
||
|
/** A template alias useful for defining proxy iterators. \see
|
||
|
`iterator_interface`. */
|
||
|
template<
|
||
|
typename Derived,
|
||
|
typename IteratorConcept,
|
||
|
typename ValueType,
|
||
|
typename Reference = ValueType,
|
||
|
typename DifferenceType = std::ptrdiff_t>
|
||
|
using proxy_iterator_interface = iterator_interface<
|
||
|
Derived,
|
||
|
IteratorConcept,
|
||
|
ValueType,
|
||
|
Reference,
|
||
|
proxy_arrow_result<Reference>,
|
||
|
DifferenceType>;
|
||
|
|
||
|
}}}
|
||
|
|
||
|
#endif
|
||
|
|
||
|
#ifdef BOOST_STL_INTERFACES_DOXYGEN
|
||
|
|
||
|
/** `static_asserts` that type `type` models concept `concept_name`. This is
|
||
|
useful for checking that an iterator, view, etc. that you write using one
|
||
|
of the *`_interface` templates models the right C++ concept.
|
||
|
|
||
|
For example: `BOOST_STL_INTERFACES_STATIC_ASSERT_CONCEPT(my_iter,
|
||
|
std::input_iterator)`.
|
||
|
|
||
|
\note This macro expands to nothing when `__cpp_lib_concepts` is not
|
||
|
defined. */
|
||
|
#define BOOST_STL_INTERFACES_STATIC_ASSERT_CONCEPT(type, concept_name)
|
||
|
|
||
|
/** `static_asserts` that the types of all typedefs in
|
||
|
`std::iterator_traits<iter>` match the remaining macro parameters. This
|
||
|
is useful for checking that an iterator you write using
|
||
|
`iterator_interface` has the correct iterator traits.
|
||
|
|
||
|
For example: `BOOST_STL_INTERFACES_STATIC_ASSERT_ITERATOR_TRAITS(my_iter,
|
||
|
std::input_iterator_tag, std::input_iterator, int, int &, int *, std::ptrdiff_t)`.
|
||
|
|
||
|
\note This macro ignores the `concept` parameter when `__cpp_lib_concepts`
|
||
|
is not defined. */
|
||
|
#define BOOST_STL_INTERFACES_STATIC_ASSERT_ITERATOR_TRAITS( \
|
||
|
iter, category, concept, value_type, reference, pointer, difference_type)
|
||
|
|
||
|
#else
|
||
|
|
||
|
#define BOOST_STL_INTERFACES_STATIC_ASSERT_ITERATOR_CONCEPT_IMPL( \
|
||
|
type, concept_name) \
|
||
|
static_assert(concept_name<type>, "");
|
||
|
|
||
|
#if BOOST_STL_INTERFACES_USE_CONCEPTS
|
||
|
#define BOOST_STL_INTERFACES_STATIC_ASSERT_CONCEPT(iter, concept_name) \
|
||
|
BOOST_STL_INTERFACES_STATIC_ASSERT_ITERATOR_CONCEPT_IMPL(iter, concept_name)
|
||
|
#else
|
||
|
#define BOOST_STL_INTERFACES_STATIC_ASSERT_CONCEPT(iter, concept_name)
|
||
|
#endif
|
||
|
|
||
|
#define BOOST_STL_INTERFACES_STATIC_ASSERT_ITERATOR_TRAITS_IMPL( \
|
||
|
iter, category, value_t, ref, ptr, diff_t) \
|
||
|
static_assert( \
|
||
|
std::is_same< \
|
||
|
typename std::iterator_traits<iter>::iterator_category, \
|
||
|
category>::value, \
|
||
|
""); \
|
||
|
static_assert( \
|
||
|
std::is_same< \
|
||
|
typename std::iterator_traits<iter>::value_type, \
|
||
|
value_t>::value, \
|
||
|
""); \
|
||
|
static_assert( \
|
||
|
std::is_same<typename std::iterator_traits<iter>::reference, ref>:: \
|
||
|
value, \
|
||
|
""); \
|
||
|
static_assert( \
|
||
|
std::is_same<typename std::iterator_traits<iter>::pointer, ptr>:: \
|
||
|
value, \
|
||
|
""); \
|
||
|
static_assert( \
|
||
|
std::is_same< \
|
||
|
typename std::iterator_traits<iter>::difference_type, \
|
||
|
diff_t>::value, \
|
||
|
"");
|
||
|
|
||
|
#if BOOST_STL_INTERFACES_USE_CONCEPTS
|
||
|
#define BOOST_STL_INTERFACES_STATIC_ASSERT_ITERATOR_TRAITS( \
|
||
|
iter, category, concept, value_type, reference, pointer, difference_type) \
|
||
|
static_assert( \
|
||
|
std::is_same_v< \
|
||
|
boost::stl_interfaces::v2::v2_dtl::iter_concept_t<iter>, \
|
||
|
concept>, \
|
||
|
""); \
|
||
|
BOOST_STL_INTERFACES_STATIC_ASSERT_ITERATOR_TRAITS_IMPL( \
|
||
|
iter, category, value_type, reference, pointer, difference_type)
|
||
|
#else
|
||
|
#define BOOST_STL_INTERFACES_STATIC_ASSERT_ITERATOR_TRAITS( \
|
||
|
iter, category, concept, value_type, reference, pointer, difference_type) \
|
||
|
BOOST_STL_INTERFACES_STATIC_ASSERT_ITERATOR_TRAITS_IMPL( \
|
||
|
iter, category, value_type, reference, pointer, difference_type)
|
||
|
#endif
|
||
|
|
||
|
#endif
|
||
|
|
||
|
#endif
|