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|
// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===---------------------------------------------------------------------===//
#ifndef _LIBCPP_SPAN
#define _LIBCPP_SPAN
/*
span synopsis
namespace std {
// constants
inline constexpr size_t dynamic_extent = numeric_limits<size_t>::max();
template<class T>
concept integral-constant-like = // exposition only, since C++26
is_integral_v<decltype(T::value)> &&
!is_same_v<bool, remove_const_t<decltype(T::value)>> &&
convertible_to<T, decltype(T::value)> &&
equality_comparable_with<T, decltype(T::value)> &&
bool_constant<T() == T::value>::value &&
bool_constant<static_cast<decltype(T::value)>(T()) == T::value>::value;
template<class T>
constexpr size_t maybe-static-ext = dynamic_extent; // exposition only, since C++26
template<integral-constant-like T>
constexpr size_t maybe-static-ext<T> = {T::value};
// [views.span], class template span
template <class ElementType, size_t Extent = dynamic_extent>
class span;
template<class ElementType, size_t Extent>
inline constexpr bool ranges::enable_view<span<ElementType, Extent>> = true;
template<class ElementType, size_t Extent>
inline constexpr bool ranges::enable_borrowed_range<span<ElementType, Extent>> = true;
// [span.objectrep], views of object representation
template <class ElementType, size_t Extent>
span<const byte, ((Extent == dynamic_extent) ? dynamic_extent :
(sizeof(ElementType) * Extent))> as_bytes(span<ElementType, Extent> s) noexcept;
template <class ElementType, size_t Extent>
span< byte, ((Extent == dynamic_extent) ? dynamic_extent :
(sizeof(ElementType) * Extent))> as_writable_bytes(span<ElementType, Extent> s) noexcept;
template <class ElementType, size_t Extent = dynamic_extent>
class span {
public:
// constants and types
using element_type = ElementType;
using value_type = remove_cv_t<ElementType>;
using size_type = size_t;
using difference_type = ptrdiff_t;
using pointer = element_type*;
using const_pointer = const element_type*;
using reference = element_type&;
using const_reference = const element_type&;
using iterator = implementation-defined;
using reverse_iterator = std::reverse_iterator<iterator>;
static constexpr size_type extent = Extent;
// [span.cons], span constructors, copy, assignment, and destructor
constexpr span() noexcept;
template <class It>
constexpr explicit(Extent != dynamic_extent) span(It first, size_type count);
template <class It, class End>
constexpr explicit(Extent != dynamic_extent) span(It first, End last);
template <size_t N>
constexpr span(type_identity_t<element_type> (&arr)[N]) noexcept;
template <size_t N>
constexpr span(array<value_type, N>& arr) noexcept;
template <size_t N>
constexpr span(const array<value_type, N>& arr) noexcept;
template<class R>
constexpr explicit(Extent != dynamic_extent) span(R&& r);
constexpr explicit(extent != dynamic_extent) span(std::initializer_list<value_type> il); // Since C++26
constexpr span(const span& other) noexcept = default;
template <class OtherElementType, size_t OtherExtent>
constexpr explicit(Extent != dynamic_extent) span(const span<OtherElementType, OtherExtent>& s) noexcept;
constexpr span& operator=(const span& other) noexcept = default;
// [span.sub], span subviews
template <size_t Count>
constexpr span<element_type, Count> first() const;
template <size_t Count>
constexpr span<element_type, Count> last() const;
template <size_t Offset, size_t Count = dynamic_extent>
constexpr span<element_type, see below> subspan() const;
constexpr span<element_type, dynamic_extent> first(size_type count) const;
constexpr span<element_type, dynamic_extent> last(size_type count) const;
constexpr span<element_type, dynamic_extent> subspan(size_type offset, size_type count = dynamic_extent) const;
// [span.obs], span observers
constexpr size_type size() const noexcept;
constexpr size_type size_bytes() const noexcept;
[[nodiscard]] constexpr bool empty() const noexcept;
// [span.elem], span element access
constexpr reference operator[](size_type idx) const;
constexpr reference at(size_type idx) const; // since C++26
constexpr reference front() const;
constexpr reference back() const;
constexpr pointer data() const noexcept;
// [span.iterators], span iterator support
constexpr iterator begin() const noexcept;
constexpr iterator end() const noexcept;
constexpr reverse_iterator rbegin() const noexcept;
constexpr reverse_iterator rend() const noexcept;
private:
pointer data_; // exposition only
size_type size_; // exposition only
};
template<class It, class EndOrSize>
span(It, EndOrSize) -> span<remove_reference_t<iter_reference_t<_It>>>; // until C++26
template<class It, class EndOrSize>
span(It, EndOrSize) -> span<remove_reference_t<iter_reference_t<It>>, maybe-static-ext<EndOrSize>>; // since C++26
template<class T, size_t N>
span(T (&)[N]) -> span<T, N>;
template<class T, size_t N>
span(array<T, N>&) -> span<T, N>;
template<class T, size_t N>
span(const array<T, N>&) -> span<const T, N>;
template<class R>
span(R&&) -> span<remove_reference_t<ranges::range_reference_t<R>>>;
} // namespace std
*/
#include <__assert>
#include <__concepts/convertible_to.h>
#include <__concepts/equality_comparable.h>
#include <__config>
#include <__fwd/array.h>
#include <__fwd/span.h>
#include <__iterator/bounded_iter.h>
#include <__iterator/concepts.h>
#include <__iterator/iterator_traits.h>
#include <__iterator/reverse_iterator.h>
#include <__iterator/wrap_iter.h>
#include <__memory/pointer_traits.h>
#include <__ranges/concepts.h>
#include <__ranges/data.h>
#include <__ranges/enable_borrowed_range.h>
#include <__ranges/enable_view.h>
#include <__ranges/size.h>
#include <__type_traits/integral_constant.h>
#include <__type_traits/is_array.h>
#include <__type_traits/is_const.h>
#include <__type_traits/is_convertible.h>
#include <__type_traits/is_integral.h>
#include <__type_traits/is_same.h>
#include <__type_traits/remove_const.h>
#include <__type_traits/remove_cv.h>
#include <__type_traits/remove_cvref.h>
#include <__type_traits/remove_reference.h>
#include <__type_traits/type_identity.h>
#include <__utility/forward.h>
#include <cstddef> // for byte
#include <initializer_list>
#include <stdexcept>
#include <version>
// standard-mandated includes
// [iterator.range]
#include <__iterator/access.h>
#include <__iterator/data.h>
#include <__iterator/empty.h>
#include <__iterator/reverse_access.h>
#include <__iterator/size.h>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_PUSH_MACROS
#include <__undef_macros>
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER >= 20
template <class _Tp>
struct __is_std_span : false_type {};
template <class _Tp, size_t _Sz>
struct __is_std_span<span<_Tp, _Sz>> : true_type {};
template <class _Range, class _ElementType>
concept __span_compatible_range =
ranges::contiguous_range<_Range> && //
ranges::sized_range<_Range> && //
(ranges::borrowed_range<_Range> || is_const_v<_ElementType>) && //
!__is_std_span<remove_cvref_t<_Range>>::value && //
!__is_std_array<remove_cvref_t<_Range>>::value && //
!is_array_v<remove_cvref_t<_Range>> && //
is_convertible_v<remove_reference_t<ranges::range_reference_t<_Range>> (*)[], _ElementType (*)[]>;
template <class _From, class _To>
concept __span_array_convertible = is_convertible_v<_From (*)[], _To (*)[]>;
template <class _It, class _Tp>
concept __span_compatible_iterator =
contiguous_iterator<_It> && __span_array_convertible<remove_reference_t<iter_reference_t<_It>>, _Tp>;
template <class _Sentinel, class _It>
concept __span_compatible_sentinel_for = sized_sentinel_for<_Sentinel, _It> && !is_convertible_v<_Sentinel, size_t>;
template <typename _Tp, size_t _Extent>
class _LIBCPP_TEMPLATE_VIS span {
public:
// constants and types
using element_type = _Tp;
using value_type = remove_cv_t<_Tp>;
using size_type = size_t;
using difference_type = ptrdiff_t;
using pointer = _Tp*;
using const_pointer = const _Tp*;
using reference = _Tp&;
using const_reference = const _Tp&;
# ifdef _LIBCPP_ABI_BOUNDED_ITERATORS
using iterator = __bounded_iter<pointer>;
# else
using iterator = __wrap_iter<pointer>;
# endif
using reverse_iterator = std::reverse_iterator<iterator>;
static constexpr size_type extent = _Extent;
// [span.cons], span constructors, copy, assignment, and destructor
template <size_t _Sz = _Extent>
requires(_Sz == 0)
_LIBCPP_HIDE_FROM_ABI constexpr span() noexcept : __data_{nullptr} {}
# if _LIBCPP_STD_VER >= 26
_LIBCPP_HIDE_FROM_ABI constexpr explicit span(std::initializer_list<value_type> __il)
requires is_const_v<element_type>
: __data_{__il.begin()} {
_LIBCPP_ASSERT_VALID_INPUT_RANGE(
_Extent == __il.size(), "Size mismatch in span's constructor _Extent != __il.size().");
}
# endif
constexpr span(const span&) noexcept = default;
constexpr span& operator=(const span&) noexcept = default;
template <__span_compatible_iterator<element_type> _It>
_LIBCPP_HIDE_FROM_ABI constexpr explicit span(_It __first, size_type __count) : __data_{std::to_address(__first)} {
(void)__count;
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(_Extent == __count, "size mismatch in span's constructor (iterator, len)");
}
template <__span_compatible_iterator<element_type> _It, __span_compatible_sentinel_for<_It> _End>
_LIBCPP_HIDE_FROM_ABI constexpr explicit span(_It __first, _End __last) : __data_{std::to_address(__first)} {
// [span.cons]/10
// Throws: When and what last - first throws.
[[maybe_unused]] auto __dist = __last - __first;
_LIBCPP_ASSERT_VALID_INPUT_RANGE(__dist >= 0, "invalid range in span's constructor (iterator, sentinel)");
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
__dist == _Extent, "invalid range in span's constructor (iterator, sentinel): last - first != extent");
}
_LIBCPP_HIDE_FROM_ABI constexpr span(type_identity_t<element_type> (&__arr)[_Extent]) noexcept : __data_{__arr} {}
template <__span_array_convertible<element_type> _OtherElementType>
_LIBCPP_HIDE_FROM_ABI constexpr span(array<_OtherElementType, _Extent>& __arr) noexcept : __data_{__arr.data()} {}
template <class _OtherElementType>
requires __span_array_convertible<const _OtherElementType, element_type>
_LIBCPP_HIDE_FROM_ABI constexpr span(const array<_OtherElementType, _Extent>& __arr) noexcept
: __data_{__arr.data()} {}
template <__span_compatible_range<element_type> _Range>
_LIBCPP_HIDE_FROM_ABI constexpr explicit span(_Range&& __r) : __data_{ranges::data(__r)} {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(ranges::size(__r) == _Extent, "size mismatch in span's constructor (range)");
}
template <__span_array_convertible<element_type> _OtherElementType>
_LIBCPP_HIDE_FROM_ABI constexpr span(const span<_OtherElementType, _Extent>& __other) noexcept
: __data_{__other.data()} {}
template <__span_array_convertible<element_type> _OtherElementType>
_LIBCPP_HIDE_FROM_ABI constexpr explicit span(const span<_OtherElementType, dynamic_extent>& __other) noexcept
: __data_{__other.data()} {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(_Extent == __other.size(), "size mismatch in span's constructor (other span)");
}
template <size_t _Count>
_LIBCPP_HIDE_FROM_ABI constexpr span<element_type, _Count> first() const noexcept {
static_assert(_Count <= _Extent, "span<T, N>::first<Count>(): Count out of range");
return span<element_type, _Count>{data(), _Count};
}
template <size_t _Count>
_LIBCPP_HIDE_FROM_ABI constexpr span<element_type, _Count> last() const noexcept {
static_assert(_Count <= _Extent, "span<T, N>::last<Count>(): Count out of range");
return span<element_type, _Count>{data() + size() - _Count, _Count};
}
_LIBCPP_HIDE_FROM_ABI constexpr span<element_type, dynamic_extent> first(size_type __count) const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__count <= size(), "span<T, N>::first(count): count out of range");
return {data(), __count};
}
_LIBCPP_HIDE_FROM_ABI constexpr span<element_type, dynamic_extent> last(size_type __count) const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__count <= size(), "span<T, N>::last(count): count out of range");
return {data() + size() - __count, __count};
}
template <size_t _Offset, size_t _Count = dynamic_extent>
_LIBCPP_HIDE_FROM_ABI constexpr auto
subspan() const noexcept -> span<element_type, _Count != dynamic_extent ? _Count : _Extent - _Offset> {
static_assert(_Offset <= _Extent, "span<T, N>::subspan<Offset, Count>(): Offset out of range");
static_assert(_Count == dynamic_extent || _Count <= _Extent - _Offset,
"span<T, N>::subspan<Offset, Count>(): Offset + Count out of range");
using _ReturnType = span<element_type, _Count != dynamic_extent ? _Count : _Extent - _Offset>;
return _ReturnType{data() + _Offset, _Count == dynamic_extent ? size() - _Offset : _Count};
}
_LIBCPP_HIDE_FROM_ABI constexpr span<element_type, dynamic_extent>
subspan(size_type __offset, size_type __count = dynamic_extent) const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__offset <= size(), "span<T, N>::subspan(offset, count): offset out of range");
if (__count == dynamic_extent)
return {data() + __offset, size() - __offset};
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
__count <= size() - __offset, "span<T, N>::subspan(offset, count): offset + count out of range");
return {data() + __offset, __count};
}
_LIBCPP_HIDE_FROM_ABI constexpr size_type size() const noexcept { return _Extent; }
_LIBCPP_HIDE_FROM_ABI constexpr size_type size_bytes() const noexcept { return _Extent * sizeof(element_type); }
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool empty() const noexcept { return _Extent == 0; }
_LIBCPP_HIDE_FROM_ABI constexpr reference operator[](size_type __idx) const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__idx < size(), "span<T, N>::operator[](index): index out of range");
return __data_[__idx];
}
# if _LIBCPP_STD_VER >= 26
_LIBCPP_HIDE_FROM_ABI constexpr reference at(size_type __index) const {
if (__index >= size())
std::__throw_out_of_range("span");
return __data_[__index];
}
# endif
_LIBCPP_HIDE_FROM_ABI constexpr reference front() const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "span<T, N>::front() on empty span");
return __data_[0];
}
_LIBCPP_HIDE_FROM_ABI constexpr reference back() const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "span<T, N>::back() on empty span");
return __data_[size() - 1];
}
_LIBCPP_HIDE_FROM_ABI constexpr pointer data() const noexcept { return __data_; }
// [span.iter], span iterator support
_LIBCPP_HIDE_FROM_ABI constexpr iterator begin() const noexcept {
# ifdef _LIBCPP_ABI_BOUNDED_ITERATORS
return std::__make_bounded_iter(data(), data(), data() + size());
# else
return iterator(data());
# endif
}
_LIBCPP_HIDE_FROM_ABI constexpr iterator end() const noexcept {
# ifdef _LIBCPP_ABI_BOUNDED_ITERATORS
return std::__make_bounded_iter(data() + size(), data(), data() + size());
# else
return iterator(data() + size());
# endif
}
_LIBCPP_HIDE_FROM_ABI constexpr reverse_iterator rbegin() const noexcept { return reverse_iterator(end()); }
_LIBCPP_HIDE_FROM_ABI constexpr reverse_iterator rend() const noexcept { return reverse_iterator(begin()); }
_LIBCPP_HIDE_FROM_ABI span<const byte, _Extent * sizeof(element_type)> __as_bytes() const noexcept {
return span<const byte, _Extent * sizeof(element_type)>{reinterpret_cast<const byte*>(data()), size_bytes()};
}
_LIBCPP_HIDE_FROM_ABI span<byte, _Extent * sizeof(element_type)> __as_writable_bytes() const noexcept {
return span<byte, _Extent * sizeof(element_type)>{reinterpret_cast<byte*>(data()), size_bytes()};
}
private:
pointer __data_;
};
template <typename _Tp>
class _LIBCPP_TEMPLATE_VIS span<_Tp, dynamic_extent> {
public:
// constants and types
using element_type = _Tp;
using value_type = remove_cv_t<_Tp>;
using size_type = size_t;
using difference_type = ptrdiff_t;
using pointer = _Tp*;
using const_pointer = const _Tp*;
using reference = _Tp&;
using const_reference = const _Tp&;
# ifdef _LIBCPP_ABI_BOUNDED_ITERATORS
using iterator = __bounded_iter<pointer>;
# else
using iterator = __wrap_iter<pointer>;
# endif
using reverse_iterator = std::reverse_iterator<iterator>;
static constexpr size_type extent = dynamic_extent;
// [span.cons], span constructors, copy, assignment, and destructor
_LIBCPP_HIDE_FROM_ABI constexpr span() noexcept : __data_{nullptr}, __size_{0} {}
# if _LIBCPP_STD_VER >= 26
_LIBCPP_HIDE_FROM_ABI constexpr span(std::initializer_list<value_type> __il)
requires is_const_v<element_type>
: __data_{__il.begin()}, __size_{__il.size()} {}
# endif
constexpr span(const span&) noexcept = default;
constexpr span& operator=(const span&) noexcept = default;
template <__span_compatible_iterator<element_type> _It>
_LIBCPP_HIDE_FROM_ABI constexpr span(_It __first, size_type __count)
: __data_{std::to_address(__first)}, __size_{__count} {}
template <__span_compatible_iterator<element_type> _It, __span_compatible_sentinel_for<_It> _End>
_LIBCPP_HIDE_FROM_ABI constexpr span(_It __first, _End __last)
: __data_(std::to_address(__first)), __size_(__last - __first) {
_LIBCPP_ASSERT_VALID_INPUT_RANGE(__last - __first >= 0, "invalid range in span's constructor (iterator, sentinel)");
}
template <size_t _Sz>
_LIBCPP_HIDE_FROM_ABI constexpr span(type_identity_t<element_type> (&__arr)[_Sz]) noexcept
: __data_{__arr}, __size_{_Sz} {}
template <__span_array_convertible<element_type> _OtherElementType, size_t _Sz>
_LIBCPP_HIDE_FROM_ABI constexpr span(array<_OtherElementType, _Sz>& __arr) noexcept
: __data_{__arr.data()}, __size_{_Sz} {}
template <class _OtherElementType, size_t _Sz>
requires __span_array_convertible<const _OtherElementType, element_type>
_LIBCPP_HIDE_FROM_ABI constexpr span(const array<_OtherElementType, _Sz>& __arr) noexcept
: __data_{__arr.data()}, __size_{_Sz} {}
template <__span_compatible_range<element_type> _Range>
_LIBCPP_HIDE_FROM_ABI constexpr span(_Range&& __r) : __data_(ranges::data(__r)), __size_{ranges::size(__r)} {}
template <__span_array_convertible<element_type> _OtherElementType, size_t _OtherExtent>
_LIBCPP_HIDE_FROM_ABI constexpr span(const span<_OtherElementType, _OtherExtent>& __other) noexcept
: __data_{__other.data()}, __size_{__other.size()} {}
template <size_t _Count>
_LIBCPP_HIDE_FROM_ABI constexpr span<element_type, _Count> first() const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(_Count <= size(), "span<T>::first<Count>(): Count out of range");
return span<element_type, _Count>{data(), _Count};
}
template <size_t _Count>
_LIBCPP_HIDE_FROM_ABI constexpr span<element_type, _Count> last() const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(_Count <= size(), "span<T>::last<Count>(): Count out of range");
return span<element_type, _Count>{data() + size() - _Count, _Count};
}
_LIBCPP_HIDE_FROM_ABI constexpr span<element_type, dynamic_extent> first(size_type __count) const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__count <= size(), "span<T>::first(count): count out of range");
return {data(), __count};
}
_LIBCPP_HIDE_FROM_ABI constexpr span<element_type, dynamic_extent> last(size_type __count) const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__count <= size(), "span<T>::last(count): count out of range");
return {data() + size() - __count, __count};
}
template <size_t _Offset, size_t _Count = dynamic_extent>
_LIBCPP_HIDE_FROM_ABI constexpr span<element_type, _Count> subspan() const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(_Offset <= size(), "span<T>::subspan<Offset, Count>(): Offset out of range");
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(_Count == dynamic_extent || _Count <= size() - _Offset,
"span<T>::subspan<Offset, Count>(): Offset + Count out of range");
return span<element_type, _Count>{data() + _Offset, _Count == dynamic_extent ? size() - _Offset : _Count};
}
constexpr span<element_type, dynamic_extent> _LIBCPP_HIDE_FROM_ABI
subspan(size_type __offset, size_type __count = dynamic_extent) const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__offset <= size(), "span<T>::subspan(offset, count): offset out of range");
if (__count == dynamic_extent)
return {data() + __offset, size() - __offset};
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(
__count <= size() - __offset, "span<T>::subspan(offset, count): offset + count out of range");
return {data() + __offset, __count};
}
_LIBCPP_HIDE_FROM_ABI constexpr size_type size() const noexcept { return __size_; }
_LIBCPP_HIDE_FROM_ABI constexpr size_type size_bytes() const noexcept { return __size_ * sizeof(element_type); }
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool empty() const noexcept { return __size_ == 0; }
_LIBCPP_HIDE_FROM_ABI constexpr reference operator[](size_type __idx) const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(__idx < size(), "span<T>::operator[](index): index out of range");
return __data_[__idx];
}
# if _LIBCPP_STD_VER >= 26
_LIBCPP_HIDE_FROM_ABI constexpr reference at(size_type __index) const {
if (__index >= size())
std::__throw_out_of_range("span");
return __data_[__index];
}
# endif
_LIBCPP_HIDE_FROM_ABI constexpr reference front() const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "span<T>::front() on empty span");
return __data_[0];
}
_LIBCPP_HIDE_FROM_ABI constexpr reference back() const noexcept {
_LIBCPP_ASSERT_VALID_ELEMENT_ACCESS(!empty(), "span<T>::back() on empty span");
return __data_[size() - 1];
}
_LIBCPP_HIDE_FROM_ABI constexpr pointer data() const noexcept { return __data_; }
// [span.iter], span iterator support
_LIBCPP_HIDE_FROM_ABI constexpr iterator begin() const noexcept {
# ifdef _LIBCPP_ABI_BOUNDED_ITERATORS
return std::__make_bounded_iter(data(), data(), data() + size());
# else
return iterator(data());
# endif
}
_LIBCPP_HIDE_FROM_ABI constexpr iterator end() const noexcept {
# ifdef _LIBCPP_ABI_BOUNDED_ITERATORS
return std::__make_bounded_iter(data() + size(), data(), data() + size());
# else
return iterator(data() + size());
# endif
}
_LIBCPP_HIDE_FROM_ABI constexpr reverse_iterator rbegin() const noexcept { return reverse_iterator(end()); }
_LIBCPP_HIDE_FROM_ABI constexpr reverse_iterator rend() const noexcept { return reverse_iterator(begin()); }
_LIBCPP_HIDE_FROM_ABI span<const byte, dynamic_extent> __as_bytes() const noexcept {
return {reinterpret_cast<const byte*>(data()), size_bytes()};
}
_LIBCPP_HIDE_FROM_ABI span<byte, dynamic_extent> __as_writable_bytes() const noexcept {
return {reinterpret_cast<byte*>(data()), size_bytes()};
}
private:
pointer __data_;
size_type __size_;
};
template <class _Tp, size_t _Extent>
inline constexpr bool ranges::enable_borrowed_range<span<_Tp, _Extent> > = true;
template <class _ElementType, size_t _Extent>
inline constexpr bool ranges::enable_view<span<_ElementType, _Extent>> = true;
// as_bytes & as_writable_bytes
template <class _Tp, size_t _Extent>
_LIBCPP_HIDE_FROM_ABI auto as_bytes(span<_Tp, _Extent> __s) noexcept {
return __s.__as_bytes();
}
template <class _Tp, size_t _Extent>
requires(!is_const_v<_Tp>)
_LIBCPP_HIDE_FROM_ABI auto as_writable_bytes(span<_Tp, _Extent> __s) noexcept {
return __s.__as_writable_bytes();
}
# if _LIBCPP_STD_VER >= 26
template <class _Tp>
concept __integral_constant_like =
is_integral_v<decltype(_Tp::value)> && !is_same_v<bool, remove_const_t<decltype(_Tp::value)>> &&
convertible_to<_Tp, decltype(_Tp::value)> && equality_comparable_with<_Tp, decltype(_Tp::value)> &&
bool_constant<_Tp() == _Tp::value>::value &&
bool_constant<static_cast<decltype(_Tp::value)>(_Tp()) == _Tp::value>::value;
template <class _Tp>
inline constexpr size_t __maybe_static_ext = dynamic_extent;
template <__integral_constant_like _Tp>
inline constexpr size_t __maybe_static_ext<_Tp> = {_Tp::value};
template <contiguous_iterator _It, class _EndOrSize>
span(_It, _EndOrSize) -> span<remove_reference_t<iter_reference_t<_It>>, __maybe_static_ext<_EndOrSize>>;
# else
template <contiguous_iterator _It, class _EndOrSize>
span(_It, _EndOrSize) -> span<remove_reference_t<iter_reference_t<_It>>>;
# endif
template <class _Tp, size_t _Sz>
span(_Tp (&)[_Sz]) -> span<_Tp, _Sz>;
template <class _Tp, size_t _Sz>
span(array<_Tp, _Sz>&) -> span<_Tp, _Sz>;
template <class _Tp, size_t _Sz>
span(const array<_Tp, _Sz>&) -> span<const _Tp, _Sz>;
template <ranges::contiguous_range _Range>
span(_Range&&) -> span<remove_reference_t<ranges::range_reference_t<_Range>>>;
#endif // _LIBCPP_STD_VER >= 20
_LIBCPP_END_NAMESPACE_STD
_LIBCPP_POP_MACROS
#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
# include <array>
# include <concepts>
# include <functional>
# include <iterator>
# include <type_traits>
#endif
#endif // _LIBCPP_SPAN
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