标准库头文件 <mdspan> (C++23)
来自 cppreference.com
此头文件是 容器 库的一部分。
类 | |
(C++23) |
一个多维非拥有数组视图 (类模板) |
(C++23) |
某个秩的多维索引空间的描述符 (类模板) |
(C++23) |
列优先多维数组布局映射策略;最左侧范围的步长为 1 (类) |
(C++23) |
行优先多维数组布局映射策略;最右侧范围的步长为 1 (类) |
(C++23) |
具有用户定义步长的布局映射策略 (类) |
(C++26) |
列优先布局映射策略,具有大于或等于最左侧范围的填充步长 (类模板) |
(C++26) |
行优先布局映射策略,具有大于或等于最右侧范围的填充步长 (类模板) |
(C++23) |
用于对 mdspan 元素进行索引访问的类型(类模板) |
(C++26) |
一个切片说明符,表示一组定期间隔的索引,如偏移量、范围和步长所示 (类模板) |
(C++26) |
submdspan_mapping 的重载的返回类型(类模板) |
别名模板 | |
(C++23)(C++26) |
用于全动态 std::extents 的便捷别名模板 (别名模板) |
函数 | |
(C++26) |
从现有范围和切片说明符创建新的范围 (函数模板) |
(C++26) |
返回现有 mdspan 的子集的视图(函数模板) |
标签 | |
(C++26) |
一个切片说明符标签,描述指定范围内的完整索引范围 (标签) |
[编辑] 概要
// all freestanding namespace std { // class template extents template<class IndexType, size_t... Extents> class extents; // alias template dextents template<class IndexType, size_t Rank> using dextents = /* see description */; // alias template dims template<size_t Rank, class IndexType = size_t> using dims = /* see description */; // layout mapping struct layout_left; struct layout_right; struct layout_stride; template<size_t PaddingValue = dynamic_extent> struct layout_left_padded; template<size_t PaddingValue = dynamic_extent> struct layout_right_padded; // class template default_accessor template<class ElementType> class default_accessor; // class template mdspan template<class ElementType, class Extents, class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<ElementType>> class mdspan; // submdspan creation template<class OffsetType, class LengthType, class StrideType> struct strided_slice; template<class LayoutMapping> struct submdspan_mapping_result; struct full_extent_t { explicit full_extent_t() = default; }; inline constexpr full_extent_t full_extent{}; template<class IndexType, class... Extents, class... SliceSpecifiers> constexpr auto submdspan_extents(const extents<IndexType, Extents...>&, SliceSpecifiers...); // submdspan function template template<class ElementType, class Extents, class LayoutPolicy, class AccessorPolicy, class... SliceSpecifiers> constexpr auto submdspan( const mdspan<ElementType, Extents, LayoutPolicy, AccessorPolicy>& src, SliceSpecifiers... slices) -> /* see description */; template<class T, class IndexType> concept /*index-pair-like*/ = // exposition only /*pair-like*/<T> && convertible_to<tuple_element_t<0, T>, IndexType> && convertible_to<tuple_element_t<1, T>, IndexType>; }
[编辑] 类模板 std::mdspan
namespace std { template<class ElementType, class Extents, class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<ElementType>> class mdspan { public: using extents_type = Extents; using layout_type = LayoutPolicy; using accessor_type = AccessorPolicy; using mapping_type = typename layout_type::template mapping<extents_type>; using element_type = ElementType; using value_type = remove_cv_t<element_type>; using index_type = typename extents_type::index_type; using size_type = typename extents_type::size_type; using rank_type = typename extents_type::rank_type; using data_handle_type = typename accessor_type::data_handle_type; using reference = typename accessor_type::reference; static constexpr rank_type rank() noexcept { return extents_type::rank(); } static constexpr rank_type rank_dynamic() noexcept { return extents_type::rank_dynamic(); } static constexpr size_t static_extent(rank_type r) noexcept { return extents_type::static_extent(r); } constexpr index_type extent(rank_type r) const noexcept { return extents().extent(r); } // constructors constexpr mdspan(); constexpr mdspan(const mdspan& rhs) = default; constexpr mdspan(mdspan&& rhs) = default; template<class... OtherIndexTypes> constexpr explicit mdspan(data_handle_type ptr, OtherIndexTypes... exts); template<class OtherIndexType, size_t N> constexpr explicit(N != rank_dynamic()) mdspan(data_handle_type p, span<OtherIndexType, N> exts); template<class OtherIndexType, size_t N> constexpr explicit(N != rank_dynamic()) mdspan(data_handle_type p, const array<OtherIndexType, N>& exts); constexpr mdspan(data_handle_type p, const extents_type& ext); constexpr mdspan(data_handle_type p, const mapping_type& m); constexpr mdspan(data_handle_type p, const mapping_type& m, const accessor_type& a); template<class OtherElementType, class OtherExtents, class OtherLayoutPolicy, class OtherAccessorPolicy> constexpr explicit(/* see description */) mdspan(const mdspan<OtherElementType, OtherExtents, OtherLayoutPolicy, OtherAccessorPolicy>& other); constexpr mdspan& operator=(const mdspan& rhs) = default; constexpr mdspan& operator=(mdspan&& rhs) = default; // members template<class... OtherIndexTypes> constexpr reference operator[](OtherIndexTypes... indices) const; template<class OtherIndexType> constexpr reference operator[](span<OtherIndexType, rank()> indices) const; template<class OtherIndexType> constexpr reference operator[](const array<OtherIndexType, rank()>& indices) const; constexpr size_type size() const noexcept; constexpr bool empty() const noexcept; friend constexpr void swap(mdspan& x, mdspan& y) noexcept; constexpr const extents_type& extents() const noexcept { return /*map_*/.extents(); } constexpr const data_handle_type& data_handle() const noexcept { return /*ptr_*/; } constexpr const mapping_type& mapping() const noexcept { return /*map_*/; } constexpr const accessor_type& accessor() const noexcept { return /*acc_*/; } static constexpr bool is_always_unique() { return mapping_type::is_always_unique(); } static constexpr bool is_always_exhaustive() { return mapping_type::is_always_exhaustive(); } static constexpr bool is_always_strided() { return mapping_type::is_always_strided(); } constexpr bool is_unique() const { return /*map_*/.is_unique(); } constexpr bool is_exhaustive() const { return /*map_*/.is_exhaustive(); } constexpr bool is_strided() const { return /*map_*/.is_strided(); } constexpr index_type stride(rank_type r) const { return /*map_*/.stride(r); } private: accessor_type /*acc_*/; // exposition only mapping_type /*map_*/; // exposition only data_handle_type /*ptr_*/; // exposition only }; template<class CArray> requires(is_array_v<CArray> && rank_v<CArray> == 1) mdspan(CArray&) -> mdspan<remove_all_extents_t<CArray>, extents<size_t, extent_v<CArray, 0>>>; template<class Pointer> requires(is_pointer_v<remove_reference_t<Pointer>>) mdspan(Pointer&&) -> mdspan<remove_pointer_t<remove_reference_t<Pointer>>, extents<size_t>>; template<class ElementType, class... Integrals> requires((is_convertible_v<Integrals, size_t> && ...) && sizeof...(Integrals) > 0) explicit mdspan(ElementType*, Integrals...) -> mdspan<ElementType, extents<size_t, /*maybe-static-ext*/<Integrals>...>>; template<class ElementType, class OtherIndexType, size_t N> mdspan(ElementType*, span<OtherIndexType, N>) -> mdspan<ElementType, dextents<size_t, N>>; template<class ElementType, class OtherIndexType, size_t N> mdspan(ElementType*, const array<OtherIndexType, N>&) -> mdspan<ElementType, dextents<size_t, N>>; template<class ElementType, class IndexType, size_t... ExtentsPack> mdspan(ElementType*, const extents<IndexType, ExtentsPack...>&) -> mdspan<ElementType, extents<IndexType, ExtentsPack...>>; template<class ElementType, class MappingType> mdspan(ElementType*, const MappingType&) -> mdspan<ElementType, typename MappingType::extents_type, typename MappingType::layout_type>; template<class MappingType, class AccessorType> mdspan(const typename AccessorType::data_handle_type&, const MappingType&, const AccessorType&) -> mdspan<typename AccessorType::element_type, typename MappingType::extents_type, typename MappingType::layout_type, AccessorType>; }
[编辑] 类模板 std::extents
namespace std { template<class IndexType, size_t... Extents> class extents { public: using index_type = IndexType; using size_type = make_unsigned_t<index_type>; using rank_type = size_t; // observers of the multidimensional index space static constexpr rank_type rank() noexcept { return sizeof...(Extents); } static constexpr rank_type rank_dynamic() noexcept { return /*dynamic-index*/(rank()); } static constexpr size_t static_extent(rank_type) noexcept; constexpr index_type extent(rank_type) const noexcept; // constructors constexpr extents() noexcept = default; template<class OtherIndexType, size_t... OtherExtents> constexpr explicit(/* see description */) extents(const extents<OtherIndexType, OtherExtents...>&) noexcept; template<class... OtherIndexTypes> constexpr explicit extents(OtherIndexTypes...) noexcept; template<class OtherIndexType, size_t N> constexpr explicit(N != rank_dynamic()) extents(span<OtherIndexType, N>) noexcept; template<class OtherIndexType, size_t N> constexpr explicit(N != rank_dynamic()) extents(const array<OtherIndexType, N>&) noexcept; // comparison operators template<class OtherIndexType, size_t... OtherExtents> friend constexpr bool operator==( const extents&, const extents<OtherIndexType, OtherExtents...>&) noexcept; // exposition only helpers constexpr size_t /*fwd-prod-of-extents*/(rank_type) const noexcept; // exposition only constexpr size_t /*rev-prod-of-extents*/(rank_type) const noexcept; // exposition only template<class OtherIndexType> static constexpr auto /*index-cast*/(OtherIndexType&&) noexcept; // exposition only private: static constexpr rank_type /*dynamic-index*/(rank_type) noexcept; // exposition only static constexpr rank_type /*dynamic-index-inv*/( rank_type) noexcept; // exposition only array<index_type, rank_dynamic()> /*dynamic-extents*/{}; // exposition only }; template<class... Integrals> explicit extents(Integrals...)->/* see description */; }
[编辑] 布局映射策略
namespace std { struct layout_left { template<class Extents> class mapping; }; struct layout_right { template<class Extents> class mapping; }; struct layout_stride { template<class Extents> class mapping; }; template<size_t PaddingValue> struct layout_left_padded { template<class Extents> class mapping; }; template<size_t PaddingValue> struct layout_right_padded { template<class Extents> class mapping; }; }
[编辑] 类模板 std::layout_left::mapping
namespace std { template<class Extents> class layout_left::mapping { public: using extents_type = Extents; using index_type = typename extents_type::index_type; using size_type = typename extents_type::size_type; using rank_type = typename extents_type::rank_type; using layout_type = layout_left; // constructors constexpr mapping() noexcept = default; constexpr mapping(const mapping&) noexcept = default; constexpr mapping(const extents_type&) noexcept; template<class OtherExtents> constexpr explicit(!is_convertible_v<OtherExtents, extents_type>) mapping(const mapping<OtherExtents>&) noexcept; template<class OtherExtents> constexpr explicit(!is_convertible_v<OtherExtents, extents_type>) mapping(const layout_right::mapping<OtherExtents>&) noexcept; template<class LayoutLeftPaddedMapping> constexpr explicit( !is_convertible_v<typename LayoutLeftPaddedMapping::extents_type, extents_type>) mapping(const LayoutLeftPaddedMapping&) noexcept; template<class OtherExtents> constexpr explicit(extents_type::rank() > 0) mapping(const layout_stride::mapping<OtherExtents>&); constexpr mapping& operator=(const mapping&) noexcept = default; // observers constexpr const extents_type& extents() const noexcept { return /*extents_*/; } constexpr index_type required_span_size() const noexcept; template<class... Indices> constexpr index_type operator()(Indices...) const noexcept; static constexpr bool is_always_unique() noexcept { return true; } static constexpr bool is_always_exhaustive() noexcept { return true; } static constexpr bool is_always_strided() noexcept { return true; } static constexpr bool is_unique() noexcept { return true; } static constexpr bool is_exhaustive() noexcept { return true; } static constexpr bool is_strided() noexcept { return true; } constexpr index_type stride(rank_type) const noexcept; template<class OtherExtents> friend constexpr bool operator==(const mapping&, const mapping<OtherExtents>&) noexcept; private: extents_type /*extents_*/{}; // exposition only // submdspan mapping specialization template<class... SliceSpecifiers> constexpr auto /*submdspan-mapping-impl*/(SliceSpecifiers...) const // exposition only -> /* see description */; template<class... SliceSpecifiers> friend constexpr auto submdspan_mapping(const mapping& src, SliceSpecifiers... slices) { return src./*submdspan-mapping-impl*/(slices...); } }; }
[编辑] 类模板 std::layout_right::mapping
namespace std { template<class Extents> class layout_right::mapping { public: using extents_type = Extents; using index_type = typename extents_type::index_type; using size_type = typename extents_type::size_type; using rank_type = typename extents_type::rank_type; using layout_type = layout_right; // constructors constexpr mapping() noexcept = default; constexpr mapping(const mapping&) noexcept = default; constexpr mapping(const extents_type&) noexcept; template<class OtherExtents> constexpr explicit(!is_convertible_v<OtherExtents, extents_type>) mapping(const mapping<OtherExtents>&) noexcept; template<class OtherExtents> constexpr explicit(!is_convertible_v<OtherExtents, extents_type>) mapping(const layout_left::mapping<OtherExtents>&) noexcept; template<class LayoutRightPaddedMapping> constexpr explicit( !is_convertible_v<typename LayoutRightPaddedMapping::extents_type, extents_type>) mapping(const LayoutRightPaddedMapping&) noexcept; template<class OtherExtents> constexpr explicit(extents_type::rank() > 0) mapping(const layout_stride::mapping<OtherExtents>&) noexcept; constexpr mapping& operator=(const mapping&) noexcept = default; // observers constexpr const extents_type& extents() const noexcept { return /*extents_*/; } constexpr index_type required_span_size() const noexcept; template<class... Indices> constexpr index_type operator()(Indices...) const noexcept; static constexpr bool is_always_unique() noexcept { return true; } static constexpr bool is_always_exhaustive() noexcept { return true; } static constexpr bool is_always_strided() noexcept { return true; } static constexpr bool is_unique() noexcept { return true; } static constexpr bool is_exhaustive() noexcept { return true; } static constexpr bool is_strided() noexcept { return true; } constexpr index_type stride(rank_type) const noexcept; template<class OtherExtents> friend constexpr bool operator==(const mapping&, const mapping<OtherExtents>&) noexcept; private: extents_type /*extents_*/{}; // exposition only // submdspan mapping specialization template<class... SliceSpecifiers> constexpr auto /*submdspan-mapping-impl*/(SliceSpecifiers...) const // exposition only -> /* see description */; template<class... SliceSpecifiers> friend constexpr auto submdspan_mapping(const mapping& src, SliceSpecifiers... slices) { return src./*submdspan-mapping-impl*/(slices...); } }; }
[编辑] 类模板 std::layout_stride::mapping
namespace std { template<class Extents> class layout_stride::mapping { public: using extents_type = Extents; using index_type = typename extents_type::index_type; using size_type = typename extents_type::size_type; using rank_type = typename extents_type::rank_type; using layout_type = layout_stride; private: static constexpr rank_type /*rank_*/ = extents_type::rank(); // exposition only public: // constructors constexpr mapping() noexcept; constexpr mapping(const mapping&) noexcept = default; template<class OtherIndexType> constexpr mapping(const extents_type&, span<OtherIndexType, /*rank_*/>) noexcept; template<class OtherIndexType> constexpr mapping(const extents_type&, const array<OtherIndexType, /*rank_*/>&) noexcept; template<class StridedLayoutMapping> constexpr explicit(/* see description */) mapping(const StridedLayoutMapping&) noexcept; constexpr mapping& operator=(const mapping&) noexcept = default; // observers constexpr const extents_type& extents() const noexcept { return /*extents_*/; } constexpr array<index_type, /*rank_*/> strides() const noexcept { return /*strides_*/; } constexpr index_type required_span_size() const noexcept; template<class... Indices> constexpr index_type operator()(Indices...) const noexcept; static constexpr bool is_always_unique() noexcept { return true; } static constexpr bool is_always_exhaustive() noexcept { return false; } static constexpr bool is_always_strided() noexcept { return true; } static constexpr bool is_unique() noexcept { return true; } constexpr bool is_exhaustive() const noexcept; static constexpr bool is_strided() noexcept { return true; } constexpr index_type stride(rank_type i) const noexcept { return /*strides_*/[i]; } template<class OtherMapping> friend constexpr bool operator==(const mapping&, const OtherMapping&) noexcept; private: extents_type /*extents_*/{}; // exposition only array<index_type, /*rank_*/> /*strides_*/{}; // exposition only // submdspan mapping specialization template<class... SliceSpecifiers> constexpr auto /*submdspan-mapping-impl*/(SliceSpecifiers...) const // exposition only -> /* see description */; template<class... SliceSpecifiers> friend constexpr auto submdspan_mapping(const mapping& src, SliceSpecifiers... slices) { return src./*submdspan-mapping-impl*/(slices...); } }; }
[编辑] 类模板 std::layout_left_padded::mapping
namespace std { template<size_t PaddingValue> template<class Extents> class layout_left_padded<PaddingValue>::mapping { public: static constexpr size_t padding_value = PaddingValue; using extents_type = Extents; using index_type = typename extents_type::index_type; using size_type = typename extents_type::size_type; using rank_type = typename extents_type::rank_type; using layout_type = layout_left_padded<PaddingValue>; private: static constexpr size_t /*rank_*/ = extents_type::rank(); // exposition only static constexpr size_t /*first-static-extent*/ = // exposition only extents_type::static_extent(0); // exposition only members static constexpr size_t /*static-padding-stride*/ = /* see description */; // exposition only public: // constructors constexpr mapping() noexcept : mapping(extents_type{}) { } constexpr mapping(const mapping&) noexcept = default; constexpr mapping(const extents_type&); template<class OtherIndexType> constexpr mapping(const extents_type&, OtherIndexType); template<class OtherExtents> constexpr explicit(!is_convertible_v<OtherExtents, extents_type>) mapping(const layout_left::mapping<OtherExtents>&); template<class OtherExtents> constexpr explicit(extents_type::rank() > 0) mapping(const layout_stride::mapping<OtherExtents>&); template<class LayoutLeftPaddedMapping> constexpr explicit(/* see description */) mapping(const LayoutLeftPaddedMapping&); template<class LayoutRightPaddedMapping> constexpr explicit(/* see description */) mapping(const LayoutRightPaddedMapping&) noexcept; constexpr mapping& operator=(const mapping&) noexcept = default; // observers constexpr const extents_type& extents() const noexcept { return /*extents_*/; } constexpr array<index_type, rank_> strides() const noexcept; constexpr index_type required_span_size() const noexcept; template<class... Indices> constexpr index_type operator()(Indices...) const noexcept; static constexpr bool is_always_unique() noexcept { return true; } static constexpr bool is_always_exhaustive() noexcept; static constexpr bool is_always_strided() noexcept { return true; } static constexpr bool is_unique() noexcept { return true; } constexpr bool is_exhaustive() const noexcept; static constexpr bool is_strided() noexcept { return true; } constexpr index_type stride(rank_type) const noexcept; template<class LayoutLeftPaddedMapping> friend constexpr bool operator==(const mapping&, const LayoutLeftPaddedMapping&) noexcept; private: // exposition only members index_type /*stride-1*/ = /*static-padding-stride*/; // exposition only extents_type /*extents_*/{}; // exposition only // submdspan mapping specialization template<class... SliceSpecifiers> constexpr auto /*submdspan-mapping-impl*/(SliceSpecifiers...) const // exposition only -> /* see description */; template<class... SliceSpecifiers> friend constexpr auto submdspan_mapping(const mapping& src, SliceSpecifiers... slices) { return src./*submdspan-mapping-impl*/(slices...); } }; }
[编辑] 类模板 std::layout_right_padded::mapping
namespace std { template<size_t PaddingValue> template<class Extents> class layout_right_padded<PaddingValue>::mapping { public: static constexpr size_t padding_value = PaddingValue; using extents_type = Extents; using index_type = typename extents_type::index_type; using size_type = typename extents_type::size_type; using rank_type = typename extents_type::rank_type; using layout_type = layout_right_padded<PaddingValue>; private: static constexpr size_t /*rank_*/ = extents_type::rank(); // exposition only static constexpr size_t /*last-static-extent*/ = // exposition only extents_type::static_extent(/*rank_*/ - 1); // exposition only members static constexpr size_t /*static-padding-stride*/ = /* see description */; // exposition only public: // constructors constexpr mapping() noexcept : mapping(extents_type{}) { } constexpr mapping(const mapping&) noexcept = default; constexpr mapping(const extents_type&); template<class OtherIndexType> constexpr mapping(const extents_type&, OtherIndexType); template<class OtherExtents> constexpr explicit(!is_convertible_v<OtherExtents, extents_type>) mapping(const layout_right::mapping<OtherExtents>&); template<class OtherExtents> constexpr explicit(rank_ > 0) mapping(const layout_stride::mapping<OtherExtents>&); template<class LayoutRightPaddedMapping> constexpr explicit(/* see description */) mapping(const LayoutRightPaddedMapping&); template<class LayoutLeftPaddedMapping> constexpr explicit(/* see description */) mapping(const LayoutLeftPaddedMapping&) noexcept; constexpr mapping& operator=(const mapping&) noexcept = default; // observers constexpr const extents_type& extents() const noexcept { return extents_; } constexpr array<index_type, rank_> strides() const noexcept; constexpr index_type required_span_size() const noexcept; template<class... Indices> constexpr index_type operator()(Indices...) const noexcept; static constexpr bool is_always_unique() noexcept { return true; } static constexpr bool is_always_exhaustive() noexcept; static constexpr bool is_always_strided() noexcept { return true; } static constexpr bool is_unique() noexcept { return true; } constexpr bool is_exhaustive() const noexcept; static constexpr bool is_strided() noexcept { return true; } constexpr index_type stride(rank_type) const noexcept; template<class LayoutRightPaddedMapping> friend constexpr bool operator==(const mapping&, const LayoutRightPaddedMapping&) noexcept; private: // exposition only members index_type /*stride-rm2*/ = /*static-padding-stride*/; // exposition only extents_type /*extents_*/{}; // exposition only // submdspan mapping specialization template<class... SliceSpecifiers> constexpr auto /*submdspan-mapping-impl*/(SliceSpecifiers...) const // exposition only -> /* see description */; template<class... SliceSpecifiers> friend constexpr auto submdspan_mapping(const mapping& src, SliceSpecifiers... slices) { return src./*submdspan-mapping-impl*/(slices...); } }; }
[编辑] 仅作说明的帮助程序
template<class T> constexpr bool /*is-extents*/ = false; // exposition only template<class IndexType, size_t... Args> constexpr bool /*is-extents*/<extents<IndexType, Args...>> = true; // exposition only; template<class M> concept /*layout-mapping-alike*/ = requires { // exposition only requires /*is-extents*/<typename M::extents_type>; { M::is_always_strided() } -> same_as<bool>; { M::is_always_exhaustive() } -> same_as<bool>; { M::is_always_unique() } -> same_as<bool>; bool_constant<M::is_always_strided()>::value; bool_constant<M::is_always_exhaustive()>::value; bool_constant<M::is_always_unique()>::value; }; template<class T> constexpr T /*de-ice*/(T val) { return val; } template</*integral-constant-like*/ T> constexpr auto /*de-ice*/(T) { return T::value; } template<class IndexType, size_t k, class... SliceSpecifiers> constexpr IndexType /*first_*/(SliceSpecifiers... slices); template<size_t k, class Extents, class... SliceSpecifiers> constexpr auto /*last_*/(const Extents& src, SliceSpecifiers... slices); template<class IndexType, size_t N, class... SliceSpecifiers> constexpr array<IndexType, sizeof...(SliceSpecifiers)> /*src-indices*/(const array<IndexType, N>& indices, SliceSpecifiers... slices);
[编辑] 类模板 std::default_accessor
namespace std { template<class ElementType> struct default_accessor { using offset_policy = default_accessor; using element_type = ElementType; using reference = ElementType&; using data_handle_type = ElementType*; constexpr default_accessor() noexcept = default; template<class OtherElementType> constexpr default_accessor(default_accessor<OtherElementType>) noexcept; constexpr reference access(data_handle_type p, size_t i) const noexcept; constexpr data_handle_type offset(data_handle_type p, size_t i) const noexcept; }; }
[编辑] 类模板 std::strided_slice
namespace std { template<class OffsetType, class ExtentType, class StrideType> struct strided_slice { using offset_type = OffsetType; using extent_type = ExtentType; using stride_type = StrideType; [[no_unique_address]] offset_type offset{}; [[no_unique_address]] extent_type extent{}; [[no_unique_address]] stride_type stride{}; }; }
[编辑] 类模板 std::submdspan_mapping_result
namespace std { template<class LayoutMapping> struct submdspan_mapping_result { [[no_unique_address]] LayoutMapping mapping = LayoutMapping(); size_t offset{}; }; }
[编辑] 参考文献
- C++23 标准 (ISO/IEC 14882:2024)
- 24.7.4 标头
<mdspan>
概要 [mdspan.syn]
- 24.7.4 标头