// <range_access.h> -*- C++ -*-
// Copyright (C) 2010-2020 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file bits/range_access.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly. @headername{iterator}
*/
#ifndef _GLIBCXX_RANGE_ACCESS_H
#define _GLIBCXX_RANGE_ACCESS_H 1
#pragma GCC system_header
#if __cplusplus >= 201103L
#include <initializer_list>
#include <bits/iterator_concepts.h>
#include <ext/numeric_traits.h>
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @brief Return an iterator pointing to the first element of
* the container.
* @param __cont Container.
*/
template<typename _Container>
inline _GLIBCXX17_CONSTEXPR auto
begin(_Container& __cont) -> decltype(__cont.begin())
{ return __cont.begin(); }
/**
* @brief Return an iterator pointing to the first element of
* the const container.
* @param __cont Container.
*/
template<typename _Container>
inline _GLIBCXX17_CONSTEXPR auto
begin(const _Container& __cont) -> decltype(__cont.begin())
{ return __cont.begin(); }
/**
* @brief Return an iterator pointing to one past the last element of
* the container.
* @param __cont Container.
*/
template<typename _Container>
inline _GLIBCXX17_CONSTEXPR auto
end(_Container& __cont) -> decltype(__cont.end())
{ return __cont.end(); }
/**
* @brief Return an iterator pointing to one past the last element of
* the const container.
* @param __cont Container.
*/
template<typename _Container>
inline _GLIBCXX17_CONSTEXPR auto
end(const _Container& __cont) -> decltype(__cont.end())
{ return __cont.end(); }
/**
* @brief Return an iterator pointing to the first element of the array.
* @param __arr Array.
*/
template<typename _Tp, size_t _Nm>
inline _GLIBCXX14_CONSTEXPR _Tp*
begin(_Tp (&__arr)[_Nm]) noexcept
{ return __arr; }
/**
* @brief Return an iterator pointing to one past the last element
* of the array.
* @param __arr Array.
*/
template<typename _Tp, size_t _Nm>
inline _GLIBCXX14_CONSTEXPR _Tp*
end(_Tp (&__arr)[_Nm]) noexcept
{ return __arr + _Nm; }
#if __cplusplus >= 201402L
template<typename _Tp> class valarray;
// These overloads must be declared for cbegin and cend to use them.
template<typename _Tp> _Tp* begin(valarray<_Tp>&);
template<typename _Tp> const _Tp* begin(const valarray<_Tp>&);
template<typename _Tp> _Tp* end(valarray<_Tp>&);
template<typename _Tp> const _Tp* end(const valarray<_Tp>&);
/**
* @brief Return an iterator pointing to the first element of
* the const container.
* @param __cont Container.
*/
template<typename _Container>
inline constexpr auto
cbegin(const _Container& __cont) noexcept(noexcept(std::begin(__cont)))
-> decltype(std::begin(__cont))
{ return std::begin(__cont); }
/**
* @brief Return an iterator pointing to one past the last element of
* the const container.
* @param __cont Container.
*/
template<typename _Container>
inline constexpr auto
cend(const _Container& __cont) noexcept(noexcept(std::end(__cont)))
-> decltype(std::end(__cont))
{ return std::end(__cont); }
/**
* @brief Return a reverse iterator pointing to the last element of
* the container.
* @param __cont Container.
*/
template<typename _Container>
inline _GLIBCXX17_CONSTEXPR auto
rbegin(_Container& __cont) -> decltype(__cont.rbegin())
{ return __cont.rbegin(); }
/**
* @brief Return a reverse iterator pointing to the last element of
* the const container.
* @param __cont Container.
*/
template<typename _Container>
inline _GLIBCXX17_CONSTEXPR auto
rbegin(const _Container& __cont) -> decltype(__cont.rbegin())
{ return __cont.rbegin(); }
/**
* @brief Return a reverse iterator pointing one past the first element of
* the container.
* @param __cont Container.
*/
template<typename _Container>
inline _GLIBCXX17_CONSTEXPR auto
rend(_Container& __cont) -> decltype(__cont.rend())
{ return __cont.rend(); }
/**
* @brief Return a reverse iterator pointing one past the first element of
* the const container.
* @param __cont Container.
*/
template<typename _Container>
inline _GLIBCXX17_CONSTEXPR auto
rend(const _Container& __cont) -> decltype(__cont.rend())
{ return __cont.rend(); }
/**
* @brief Return a reverse iterator pointing to the last element of
* the array.
* @param __arr Array.
*/
template<typename _Tp, size_t _Nm>
inline _GLIBCXX17_CONSTEXPR reverse_iterator<_Tp*>
rbegin(_Tp (&__arr)[_Nm]) noexcept
{ return reverse_iterator<_Tp*>(__arr + _Nm); }
/**
* @brief Return a reverse iterator pointing one past the first element of
* the array.
* @param __arr Array.
*/
template<typename _Tp, size_t _Nm>
inline _GLIBCXX17_CONSTEXPR reverse_iterator<_Tp*>
rend(_Tp (&__arr)[_Nm]) noexcept
{ return reverse_iterator<_Tp*>(__arr); }
/**
* @brief Return a reverse iterator pointing to the last element of
* the initializer_list.
* @param __il initializer_list.
*/
template<typename _Tp>
inline _GLIBCXX17_CONSTEXPR reverse_iterator<const _Tp*>
rbegin(initializer_list<_Tp> __il) noexcept
{ return reverse_iterator<const _Tp*>(__il.end()); }
/**
* @brief Return a reverse iterator pointing one past the first element of
* the initializer_list.
* @param __il initializer_list.
*/
template<typename _Tp>
inline _GLIBCXX17_CONSTEXPR reverse_iterator<const _Tp*>
rend(initializer_list<_Tp> __il) noexcept
{ return reverse_iterator<const _Tp*>(__il.begin()); }
/**
* @brief Return a reverse iterator pointing to the last element of
* the const container.
* @param __cont Container.
*/
template<typename _Container>
inline _GLIBCXX17_CONSTEXPR auto
crbegin(const _Container& __cont) -> decltype(std::rbegin(__cont))
{ return std::rbegin(__cont); }
/**
* @brief Return a reverse iterator pointing one past the first element of
* the const container.
* @param __cont Container.
*/
template<typename _Container>
inline _GLIBCXX17_CONSTEXPR auto
crend(const _Container& __cont) -> decltype(std::rend(__cont))
{ return std::rend(__cont); }
#endif // C++14
#if __cplusplus >= 201703L
#define __cpp_lib_nonmember_container_access 201411
/**
* @brief Return the size of a container.
* @param __cont Container.
*/
template <typename _Container>
constexpr auto
size(const _Container& __cont) noexcept(noexcept(__cont.size()))
-> decltype(__cont.size())
{ return __cont.size(); }
/**
* @brief Return the size of an array.
*/
template <typename _Tp, size_t _Nm>
constexpr size_t
size(const _Tp (&)[_Nm]) noexcept
{ return _Nm; }
/**
* @brief Return whether a container is empty.
* @param __cont Container.
*/
template <typename _Container>
[[nodiscard]] constexpr auto
empty(const _Container& __cont) noexcept(noexcept(__cont.empty()))
-> decltype(__cont.empty())
{ return __cont.empty(); }
/**
* @brief Return whether an array is empty (always false).
*/
template <typename _Tp, size_t _Nm>
[[nodiscard]] constexpr bool
empty(const _Tp (&)[_Nm]) noexcept
{ return false; }
/**
* @brief Return whether an initializer_list is empty.
* @param __il Initializer list.
*/
template <typename _Tp>
[[nodiscard]] constexpr bool
empty(initializer_list<_Tp> __il) noexcept
{ return __il.size() == 0;}
/**
* @brief Return the data pointer of a container.
* @param __cont Container.
*/
template <typename _Container>
constexpr auto
data(_Container& __cont) noexcept(noexcept(__cont.data()))
-> decltype(__cont.data())
{ return __cont.data(); }
/**
* @brief Return the data pointer of a const container.
* @param __cont Container.
*/
template <typename _Container>
constexpr auto
data(const _Container& __cont) noexcept(noexcept(__cont.data()))
-> decltype(__cont.data())
{ return __cont.data(); }
/**
* @brief Return the data pointer of an array.
* @param __array Array.
*/
template <typename _Tp, size_t _Nm>
constexpr _Tp*
data(_Tp (&__array)[_Nm]) noexcept
{ return __array; }
/**
* @brief Return the data pointer of an initializer list.
* @param __il Initializer list.
*/
template <typename _Tp>
constexpr const _Tp*
data(initializer_list<_Tp> __il) noexcept
{ return __il.begin(); }
#endif // C++17
#if __cplusplus > 201703L
#define __cpp_lib_ssize 201902L
template<typename _Container>
constexpr auto
ssize(const _Container& __cont)
noexcept(noexcept(__cont.size()))
-> common_type_t<ptrdiff_t, make_signed_t<decltype(__cont.size())>>
{
using type = make_signed_t<decltype(__cont.size())>;
return static_cast<common_type_t<ptrdiff_t, type>>(__cont.size());
}
template<typename _Tp, ptrdiff_t _Num>
constexpr ptrdiff_t
ssize(const _Tp (&)[_Num]) noexcept
{ return _Num; }
#ifdef __cpp_lib_concepts
namespace ranges
{
template<typename>
inline constexpr bool disable_sized_range = false;
template<typename _Tp>
inline constexpr bool enable_borrowed_range = false;
template<typename _Tp>
extern const bool enable_view;
namespace __detail
{
template<integral _Tp>
constexpr auto
__to_unsigned_like(_Tp __t) noexcept
{ return static_cast<make_unsigned_t<_Tp>>(__t); }
#if defined __STRICT_ANSI__ && defined __SIZEOF_INT128__
constexpr unsigned __int128
__to_unsigned_like(__int128 __t) noexcept
{ return __t; }
constexpr unsigned __int128
__to_unsigned_like(unsigned __int128 __t) noexcept
{ return __t; }
#endif
template<typename _Tp>
using __make_unsigned_like_t
= decltype(__detail::__to_unsigned_like(std::declval<_Tp>()));
// Part of the constraints of ranges::borrowed_range
template<typename _Tp>
concept __maybe_borrowed_range
= is_lvalue_reference_v<_Tp>
|| enable_borrowed_range<remove_cvref_t<_Tp>>;
} // namespace __detail
namespace __cust_access
{
using std::ranges::__detail::__maybe_borrowed_range;
using std::__detail::__class_or_enum;
using std::__detail::__decay_copy;
using std::__detail::__member_begin;
using std::__detail::__adl_begin;
struct _Begin
{
private:
template<typename _Tp>
static constexpr bool
_S_noexcept()
{
if constexpr (is_array_v<remove_reference_t<_Tp>>)
return true;
else if constexpr (__member_begin<_Tp>)
return noexcept(__decay_copy(std::declval<_Tp&>().begin()));
else
return noexcept(__decay_copy(begin(std::declval<_Tp&>())));
}
public:
template<__maybe_borrowed_range _Tp>
requires is_array_v<remove_reference_t<_Tp>> || __member_begin<_Tp>
|| __adl_begin<_Tp>
constexpr auto
operator()(_Tp&& __t) const noexcept(_S_noexcept<_Tp>())
{
if constexpr (is_array_v<remove_reference_t<_Tp>>)
{
static_assert(is_lvalue_reference_v<_Tp>);
using _Up = remove_all_extents_t<remove_reference_t<_Tp>>;
static_assert(sizeof(_Up) != 0, "not array of incomplete type");
return __t + 0;
}
else if constexpr (__member_begin<_Tp>)
return __t.begin();
else
return begin(__t);
}
};
template<typename _Tp>
concept __member_end = requires(_Tp& __t)
{
{ __decay_copy(__t.end()) }
-> sentinel_for<decltype(_Begin{}(std::forward<_Tp>(__t)))>;
};
void end(auto&) = delete;
void end(const auto&) = delete;
template<typename _Tp>
concept __adl_end = __class_or_enum<remove_reference_t<_Tp>>
&& requires(_Tp& __t)
{
{ __decay_copy(end(__t)) }
-> sentinel_for<decltype(_Begin{}(std::forward<_Tp>(__t)))>;
};
struct _End
{
private:
template<typename _Tp>
static constexpr bool
_S_noexcept()
{
if constexpr (is_bounded_array_v<remove_reference_t<_Tp>>)
return true;
else if constexpr (__member_end<_Tp>)
return noexcept(__decay_copy(std::declval<_Tp&>().end()));
else
return noexcept(__decay_copy(end(std::declval<_Tp&>())));
}
public:
template<__maybe_borrowed_range _Tp>
requires is_bounded_array_v<remove_reference_t<_Tp>> || __member_end<_Tp>
|| __adl_end<_Tp>
constexpr auto
operator()(_Tp&& __t) const noexcept(_S_noexcept<_Tp>())
{
if constexpr (is_bounded_array_v<remove_reference_t<_Tp>>)
{
static_assert(is_lvalue_reference_v<_Tp>);
return __t + extent_v<remove_reference_t<_Tp>>;
}
else if constexpr (__member_end<_Tp>)
return __t.end();
else
return end(__t);
}
};
template<typename _Tp>
constexpr decltype(auto)
__as_const(_Tp&& __t) noexcept
{
if constexpr (is_lvalue_reference_v<_Tp>)
return static_cast<const remove_reference_t<_Tp>&>(__t);
else
return static_cast<const _Tp&&>(__t);
}
struct _CBegin
{
template<typename _Tp>
constexpr auto
operator()(_Tp&& __e) const
noexcept(noexcept(_Begin{}(__cust_access::__as_const((_Tp&&)__e))))
requires requires { _Begin{}(__cust_access::__as_const((_Tp&&)__e)); }
{
return _Begin{}(__cust_access::__as_const(std::forward<_Tp>(__e)));
}
};
struct _CEnd
{
template<typename _Tp>
constexpr auto
operator()(_Tp&& __e) const
noexcept(noexcept(_End{}(__cust_access::__as_const((_Tp&&)__e))))
requires requires { _End{}(__cust_access::__as_const((_Tp&&)__e)); }
{
return _End{}(__cust_access::__as_const(std::forward<_Tp>(__e)));
}
};
template<typename _Tp>
concept __member_rbegin = requires(_Tp& __t)
{
{ __decay_copy(__t.rbegin()) } -> input_or_output_iterator;
};
void rbegin(auto&) = delete;
void rbegin(const auto&) = delete;
template<typename _Tp>
concept __adl_rbegin = __class_or_enum<remove_reference_t<_Tp>>
&& requires(_Tp& __t)
{
{ __decay_copy(rbegin(__t)) } -> input_or_output_iterator;
};
template<typename _Tp>
concept __reversable = requires(_Tp& __t)
{
{ _Begin{}(__t) } -> bidirectional_iterator;
{ _End{}(__t) } -> same_as<decltype(_Begin{}(__t))>;
};
struct _RBegin
{
private:
template<typename _Tp>
static constexpr bool
_S_noexcept()
{
if constexpr (__member_rbegin<_Tp>)
return noexcept(__decay_copy(std::declval<_Tp&>().rbegin()));
else if constexpr (__adl_rbegin<_Tp>)
return noexcept(__decay_copy(rbegin(std::declval<_Tp&>())));
else
{
if constexpr (noexcept(_End{}(std::declval<_Tp&>())))
{
using _It = decltype(_End{}(std::declval<_Tp&>()));
// std::reverse_iterator copy-initializes its member.
return is_nothrow_copy_constructible_v<_It>;
}
else
return false;
}
}
public:
template<__maybe_borrowed_range _Tp>
requires __member_rbegin<_Tp> || __adl_rbegin<_Tp> || __reversable<_Tp>
constexpr auto
operator()(_Tp&& __t) const
noexcept(_S_noexcept<_Tp>())
{
if constexpr (__member_rbegin<_Tp>)
return __t.rbegin();
else if constexpr (__adl_rbegin<_Tp>)
return rbegin(__t);
else
return std::make_reverse_iterator(_End{}(__t));
}
};
template<typename _Tp>
concept __member_rend = requires(_Tp& __t)
{
{ __decay_copy(__t.rend()) }
-> sentinel_for<decltype(_RBegin{}(__t))>;
};
void rend(auto&) = delete;
void rend(const auto&) = delete;
template<typename _Tp>
concept __adl_rend = __class_or_enum<remove_reference_t<_Tp>>
&& requires(_Tp& __t)
{
{ __decay_copy(rend(__t)) }
-> sentinel_for<decltype(_RBegin{}(std::forward<_Tp>(__t)))>;
};
struct _REnd
{
private:
template<typename _Tp>
static constexpr bool
_S_noexcept()
{
if constexpr (__member_rend<_Tp>)
return noexcept(__decay_copy(std::declval<_Tp&>().rend()));
else if constexpr (__adl_rend<_Tp>)
return noexcept(__decay_copy(rend(std::declval<_Tp&>())));
else
{
if constexpr (noexcept(_Begin{}(std::declval<_Tp&>())))
{
using _It = decltype(_Begin{}(std::declval<_Tp&>()));
// std::reverse_iterator copy-initializes its member.
return is_nothrow_copy_constructible_v<_It>;
}
else
return false;
}
}
public:
template<__maybe_borrowed_range _Tp>
requires __member_rend<_Tp> || __adl_rend<_Tp> || __reversable<_Tp>
constexpr auto
operator()(_Tp&& __t) const
noexcept(_S_noexcept<_Tp>())
{
if constexpr (__member_rend<_Tp>)
return __t.rend();
else if constexpr (__adl_rend<_Tp>)
return rend(__t);
else
return std::make_reverse_iterator(_Begin{}(__t));
}
};
struct _CRBegin
{
template<typename _Tp>
constexpr auto
operator()(_Tp&& __e) const
noexcept(noexcept(_RBegin{}(__cust_access::__as_const((_Tp&&)__e))))
requires requires { _RBegin{}(__cust_access::__as_const((_Tp&&)__e)); }
{
return _RBegin{}(__cust_access::__as_const(std::forward<_Tp>(__e)));
}
};
struct _CREnd
{
template<typename _Tp>
constexpr auto
operator()(_Tp&& __e) const
noexcept(noexcept(_REnd{}(__cust_access::__as_const((_Tp&&)__e))))
requires requires { _REnd{}(__cust_access::__as_const((_Tp&&)__e)); }
{
return _REnd{}(__cust_access::__as_const(std::forward<_Tp>(__e)));
}
};
template<typename _Tp>
concept __member_size = !disable_sized_range<remove_cvref_t<_Tp>>
&& requires(_Tp&& __t)
{
{ __decay_copy(std::forward<_Tp>(__t).size()) }
-> __detail::__is_integer_like;
};
void size(auto&) = delete;
void size(const auto&) = delete;
template<typename _Tp>
concept __adl_size = __class_or_enum<remove_reference_t<_Tp>>
&& !disable_sized_range<remove_cvref_t<_Tp>>
&& requires(_Tp&& __t)
{
{ __decay_copy(size(std::forward<_Tp>(__t))) }
-> __detail::__is_integer_like;
};
template<typename _Tp>
concept __sentinel_size = requires(_Tp&& __t)
{
{ _Begin{}(std::forward<_Tp>(__t)) } -> forward_iterator;
{ _End{}(std::forward<_Tp>(__t)) }
-> sized_sentinel_for<decltype(_Begin{}(std::forward<_Tp>(__t)))>;
};
struct _Size
{
private:
template<typename _Tp>
static constexpr bool
_S_noexcept()
{
if constexpr (is_bounded_array_v<remove_reference_t<_Tp>>)
return true;
else if constexpr (__member_size<_Tp>)
return noexcept(__decay_copy(std::declval<_Tp>().size()));
else if constexpr (__adl_size<_Tp>)
return noexcept(__decay_copy(size(std::declval<_Tp>())));
else if constexpr (__sentinel_size<_Tp>)
return noexcept(_End{}(std::declval<_Tp>())
- _Begin{}(std::declval<_Tp>()));
}
public:
template<typename _Tp>
requires is_bounded_array_v<remove_reference_t<_Tp>>
|| __member_size<_Tp> || __adl_size<_Tp> || __sentinel_size<_Tp>
constexpr auto
operator()(_Tp&& __e) const noexcept(_S_noexcept<_Tp>())
{
if constexpr (is_bounded_array_v<remove_reference_t<_Tp>>)
{
return extent_v<remove_reference_t<_Tp>>;
}
else if constexpr (__member_size<_Tp>)
return std::forward<_Tp>(__e).size();
else if constexpr (__adl_size<_Tp>)
return size(std::forward<_Tp>(__e));
else if constexpr (__sentinel_size<_Tp>)
return __detail::__to_unsigned_like(
_End{}(std::forward<_Tp>(__e))
- _Begin{}(std::forward<_Tp>(__e)));
}
};
struct _SSize
{
template<typename _Tp>
requires requires (_Tp&& __e)
{
_Begin{}(std::forward<_Tp>(__e));
_Size{}(std::forward<_Tp>(__e));
}
constexpr auto
operator()(_Tp&& __e) const
noexcept(noexcept(_Size{}(std::forward<_Tp>(__e))))
{
using __iter_type = decltype(_Begin{}(std::forward<_Tp>(__e)));
using __diff_type = iter_difference_t<__iter_type>;
using __gnu_cxx::__int_traits;
auto __size = _Size{}(std::forward<_Tp>(__e));
if constexpr (integral<__diff_type>)
{
if constexpr (__int_traits<__diff_type>::__digits
< __int_traits<ptrdiff_t>::__digits)
return static_cast<ptrdiff_t>(__size);
}
return static_cast<__diff_type>(__size);
}
};
template<typename _Tp>
concept __member_empty = requires(_Tp&& __t)
{ bool(std::forward<_Tp>(__t).empty()); };
template<typename _Tp>
concept __size0_empty = requires(_Tp&& __t)
{ _Size{}(std::forward<_Tp>(__t)) == 0; };
template<typename _Tp>
concept __eq_iter_empty = requires(_Tp&& __t)
{
{ _Begin{}(std::forward<_Tp>(__t)) } -> forward_iterator;
bool(_Begin{}(std::forward<_Tp>(__t))
== _End{}(std::forward<_Tp>(__t)));
};
struct _Empty
{
private:
template<typename _Tp>
static constexpr bool
_S_noexcept()
{
if constexpr (__member_empty<_Tp>)
return noexcept(bool(std::declval<_Tp>().empty()));
else if constexpr (__size0_empty<_Tp>)
return noexcept(_Size{}(std::declval<_Tp>()) == 0);
else
return noexcept(bool(_Begin{}(std::declval<_Tp>())
== _End{}(std::declval<_Tp>())));
}
public:
template<typename _Tp>
requires __member_empty<_Tp> || __size0_empty<_Tp>
|| __eq_iter_empty<_Tp>
constexpr bool
operator()(_Tp&& __e) const noexcept(_S_noexcept<_Tp>())
{
if constexpr (__member_empty<_Tp>)
return bool(std::forward<_Tp>(__e).empty());
else if constexpr (__size0_empty<_Tp>)
return _Size{}(std::forward<_Tp>(__e)) == 0;
else
return bool(_Begin{}(std::forward<_Tp>(__e))
== _End{}(std::forward<_Tp>(__e)));
}
};
template<typename _Tp>
concept __pointer_to_object = is_pointer_v<_Tp>
&& is_object_v<remove_pointer_t<_Tp>>;
template<typename _Tp>
concept __member_data = is_lvalue_reference_v<_Tp>
&& requires(_Tp __t) { { __t.data() } -> __pointer_to_object; };
template<typename _Tp>
concept __begin_data = requires(_Tp&& __t)
{ { _Begin{}(std::forward<_Tp>(__t)) } -> contiguous_iterator; };
struct _Data
{
private:
template<typename _Tp>
static constexpr bool
_S_noexcept()
{
if constexpr (__member_data<_Tp>)
return noexcept(__decay_copy(std::declval<_Tp>().data()));
else
return noexcept(_Begin{}(std::declval<_Tp>()));
}
public:
template<__maybe_borrowed_range _Tp>
requires __member_data<_Tp> || __begin_data<_Tp>
constexpr auto
operator()(_Tp&& __e) const noexcept(_S_noexcept<_Tp>())
{
if constexpr (__member_data<_Tp>)
return __e.data();
else
return std::to_address(_Begin{}(std::forward<_Tp>(__e)));
}
};
struct _CData
{
template<typename _Tp>
constexpr auto
operator()(_Tp&& __e) const
noexcept(noexcept(_Data{}(__cust_access::__as_const((_Tp&&)__e))))
requires requires { _Data{}(__cust_access::__as_const((_Tp&&)__e)); }
{
return _Data{}(__cust_access::__as_const(std::forward<_Tp>(__e)));
}
};
} // namespace __cust_access
inline namespace __cust
{
inline constexpr __cust_access::_Begin begin{};
inline constexpr __cust_access::_End end{};
inline constexpr __cust_access::_CBegin cbegin{};
inline constexpr __cust_access::_CEnd cend{};
inline constexpr __cust_access::_RBegin rbegin{};
inline constexpr __cust_access::_REnd rend{};
inline constexpr __cust_access::_CRBegin crbegin{};
inline constexpr __cust_access::_CREnd crend{};
inline constexpr __cust_access::_Size size{};
inline constexpr __cust_access::_SSize ssize{};
inline constexpr __cust_access::_Empty empty{};
inline constexpr __cust_access::_Data data{};
inline constexpr __cust_access::_CData cdata{};
}
/// [range.range] The range concept.
template<typename _Tp>
concept range = requires(_Tp& __t)
{
ranges::begin(__t);
ranges::end(__t);
};
/// [range.range] The borrowed_range concept.
template<typename _Tp>
concept borrowed_range
= range<_Tp> && __detail::__maybe_borrowed_range<_Tp>;
template<typename _Tp>
using iterator_t = std::__detail::__range_iter_t<_Tp>;
template<range _Range>
using sentinel_t = decltype(ranges::end(std::declval<_Range&>()));
template<range _Range>
using range_difference_t = iter_difference_t<iterator_t<_Range>>;
template<range _Range>
using range_value_t = iter_value_t<iterator_t<_Range>>;
template<range _Range>
using range_reference_t = iter_reference_t<iterator_t<_Range>>;
template<range _Range>
using range_rvalue_reference_t
= iter_rvalue_reference_t<iterator_t<_Range>>;
/// [range.sized] The sized_range concept.
template<typename _Tp>
concept sized_range = range<_Tp>
&& requires(_Tp& __t) { ranges::size(__t); };
template<sized_range _Range>
using range_size_t = decltype(ranges::size(std::declval<_Range&>()));
// [range.refinements]
/// A range for which ranges::begin returns an output iterator.
template<typename _Range, typename _Tp>
concept output_range
= range<_Range> && output_iterator<iterator_t<_Range>, _Tp>;
/// A range for which ranges::begin returns an input iterator.
template<typename _Tp>
concept input_range = range<_Tp> && input_iterator<iterator_t<_Tp>>;
/// A range for which ranges::begin returns a forward iterator.
template<typename _Tp>
concept forward_range
= input_range<_Tp> && forward_iterator<iterator_t<_Tp>>;
/// A range for which ranges::begin returns a bidirectional iterator.
template<typename _Tp>
concept bidirectional_range
= forward_range<_Tp> && bidirectional_iterator<iterator_t<_Tp>>;
/// A range for which ranges::begin returns a random access iterator.
template<typename _Tp>
concept random_access_range
= bidirectional_range<_Tp> && random_access_iterator<iterator_t<_Tp>>;
/// A range for which ranges::begin returns a contiguous iterator.
template<typename _Tp>
concept contiguous_range
= random_access_range<_Tp> && contiguous_iterator<iterator_t<_Tp>>
&& requires(_Tp& __t)
{
{ ranges::data(__t) } -> same_as<add_pointer_t<range_reference_t<_Tp>>>;
};
/// A range for which ranges::begin and ranges::end return the same type.
template<typename _Tp>
concept common_range
= range<_Tp> && same_as<iterator_t<_Tp>, sentinel_t<_Tp>>;
// [range.iter.ops] range iterator operations
struct __advance_fn
{
template<input_or_output_iterator _It>
constexpr void
operator()(_It& __it, iter_difference_t<_It> __n) const
{
if constexpr (random_access_iterator<_It>)
__it += __n;
else if constexpr (bidirectional_iterator<_It>)
{
if (__n > 0)
{
do
{
++__it;
}
while (--__n);
}
else if (__n < 0)
{
do
{
--__it;
}
while (++__n);
}
}
else
{
#ifdef __cpp_lib_is_constant_evaluated
if (std::is_constant_evaluated() && __n < 0)
throw "attempt to decrement a non-bidirectional iterator";
#endif
__glibcxx_assert(__n >= 0);
while (__n-- > 0)
++__it;
}
}
template<input_or_output_iterator _It, sentinel_for<_It> _Sent>
constexpr void
operator()(_It& __it, _Sent __bound) const
{
if constexpr (assignable_from<_It&, _Sent>)
__it = std::move(__bound);
else if constexpr (sized_sentinel_for<_Sent, _It>)
(*this)(__it, __bound - __it);
else
{
while (__it != __bound)
++__it;
}
}
template<input_or_output_iterator _It, sentinel_for<_It> _Sent>
constexpr iter_difference_t<_It>
operator()(_It& __it, iter_difference_t<_It> __n, _Sent __bound) const
{
if constexpr (sized_sentinel_for<_Sent, _It>)
{
const auto __diff = __bound - __it;
if (__diff == 0)
return __n;
else if (__diff > 0 ? __n >= __diff : __n <= __diff)
{
(*this)(__it, __bound);
return __n - __diff;
}
else if (__n != 0) [[likely]]
{
#ifdef __cpp_lib_is_constant_evaluated
if (std::is_constant_evaluated() && !(__n < 0 == __diff < 0))
throw "inconsistent directions for distance and bound";
#endif
// n and bound must not lead in opposite directions:
__glibcxx_assert(__n < 0 == __diff < 0);
(*this)(__it, __n);
return 0;
}
else
return 0;
}
else if (__it == __bound || __n == 0)
return __n;
else if (__n > 0)
{
iter_difference_t<_It> __m = 0;
do
{
++__it;
++__m;
}
while (__m != __n && __it != __bound);
return __n - __m;
}
else if constexpr (bidirectional_iterator<_It> && same_as<_It, _Sent>)
{
iter_difference_t<_It> __m = 0;
do
{
--__it;
--__m;
}
while (__m != __n && __it != __bound);
return __n - __m;
}
else
{
#ifdef __cpp_lib_is_constant_evaluated
if (std::is_constant_evaluated() && __n < 0)
throw "attempt to decrement a non-bidirectional iterator";
#endif
__glibcxx_assert(__n >= 0);
return __n;
}
}
};
inline constexpr __advance_fn advance{};
struct __distance_fn
{
template<input_or_output_iterator _It, sentinel_for<_It> _Sent>
constexpr iter_difference_t<_It>
operator()(_It __first, _Sent __last) const
{
if constexpr (sized_sentinel_for<_Sent, _It>)
return __last - __first;
else
{
iter_difference_t<_It> __n = 0;
while (__first != __last)
{
++__first;
++__n;
}
return __n;
}
}
template<range _Range>
constexpr range_difference_t<_Range>
operator()(_Range&& __r) const
{
if constexpr (sized_range<_Range>)
return static_cast<range_difference_t<_Range>>(ranges::size(__r));
else
return (*this)(ranges::begin(__r), ranges::end(__r));
}
};
inline constexpr __distance_fn distance{};
struct __next_fn
{
template<input_or_output_iterator _It>
constexpr _It
operator()(_It __x) const
{
++__x;
return __x;
}
template<input_or_output_iterator _It>
constexpr _It
operator()(_It __x, iter_difference_t<_It> __n) const
{
ranges::advance(__x, __n);
return __x;
}
template<input_or_output_iterator _It, sentinel_for<_It> _Sent>
constexpr _It
operator()(_It __x, _Sent __bound) const
{
ranges::advance(__x, __bound);
return __x;
}
template<input_or_output_iterator _It, sentinel_for<_It> _Sent>
constexpr _It
operator()(_It __x, iter_difference_t<_It> __n, _Sent __bound) const
{
ranges::advance(__x, __n, __bound);
return __x;
}
};
inline constexpr __next_fn next{};
struct __prev_fn
{
template<bidirectional_iterator _It>
constexpr _It
operator()(_It __x) const
{
--__x;
return __x;
}
template<bidirectional_iterator _It>
constexpr _It
operator()(_It __x, iter_difference_t<_It> __n) const
{
ranges::advance(__x, -__n);
return __x;
}
template<bidirectional_iterator _It>
constexpr _It
operator()(_It __x, iter_difference_t<_It> __n, _It __bound) const
{
ranges::advance(__x, -__n, __bound);
return __x;
}
};
inline constexpr __prev_fn prev{};
} // namespace ranges
#endif // library concepts
#endif // C++20
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif // C++11
#endif // _GLIBCXX_RANGE_ACCESS_H