| // -*- 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 |