std::extents<IndexType,Extents...>::extents

 

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std::mdspan

Member functions mdspan::mdspan mdspan::operator= Element access mdspan::operator[] Observers mdspan::rank mdspan::rank_dynamic mdspan::static_extent mdspan::extent mdspan::size mdspan::empty mdspan::stride mdspan::extents mdspan::data_handle mdspan::mapping mdspan::accessor mdspan::is_uniquemdspan::is_exhaustivemdspan::is_stridedmdspan::is_always_uniquemdspan::is_always_exhaustivemdspan::is_always_strided

Non-member functions swap(std::mdspan) Subviews submdspan (C++26) submdspan_extents (C++26) Helper types and templates extentsdextentsdims (C++26) default_accessor Layout mapping policies layout_left layout_right layout_stride layout_left_padded (C++26) layout_right_padded (C++26) Subviews helpers full_extent (C++26) strided_slice (C++26) submdspan_mapping_result (C++26) Deduction guides

 

std::extents

Member functions

extents::extents

Observers

extents::rank

extents::rank_dynamic

extents::static_extent

extents::extent

Helpers

extents::fwd-prod-of-extents

extents::rev-prod-of-extents

extents::index-cast

extents::dynamic-index

extents::dynamic-index-inv

Non-member functions

extents::operator==

Deduction guides

 

constexpr extents() = default;	(1)	(since C++23)
template< class OtherIndexType, std::size_t... OtherExtents > constexpr explicit(/*see below*/)     extents( const std::extents<OtherIndexType, OtherExtents...>& other ) noexcept;	(2)	(since C++23)
template< class... OtherIndexTypes > constexpr explicit extents( OtherIndexTypes... exts ) noexcept;	(3)	(since C++23)
template< class OtherIndexType, std::size_t N > constexpr explicit(N != rank_dynamic())     extents( std::span<OtherIndexType, N> exts ) noexcept;	(4)	(since C++23)
template< class OtherIndexType, std::size_t N > constexpr explicit(N != rank_dynamic())     extents( const std::array<OtherIndexType, N>& exts ) noexcept;	(5)	(since C++23)

Construct an extents. One can construct extents from just dynamic extents, which are all the values getting stored, or from all the extents with a precondition.

1) Default constructor. Initializes all dynamic extents to zero.

2) Conversion from another extents object. After construction, *this == other is true.

• The behavior is undefined if

• other.extent(r) != static_extent(r) for any r for which static_extent(r) represents a static extent, or
• other.extent(r) is not representable as a value of type IndexType for any rank value r in other.

• This overload participates in overload resolution only if

• sizeof...(OtherExtents) == rank() is true, and
• ((OtherExtents == std::dynamic_extent || Extents == std::dynamic_extent ||
    OtherExtents == Extents) && ...) is true.

• This constructor is explicit if

• ((Extents != std::dynamic_extent && OtherExtents == std::dynamic_extent) || ...) is true, or
• std::numeric_limits<IndexType>::max() < std::numeric_limits<OtherIndexType>::max() is true.

3) Let N be sizeof...(exts) and exts_arr be std::array<IndexType, N>{static_cast<IndexType>(std::move(exts))...}, equivalent to extents(exts_arr).

• This overload participates in overload resolution only if

• (std::is_convertible_v<OtherIndexTypes, IndexType> && ...) is true,
• (std::is_nothrow_constructible_v<IndexType, OtherIndexTypes> && ...) is true, and
• N == rank_dynamic() || N == rank() is true.

• The behavior is undefined if

• N != rank_dynamic() and exts_arr[r] is not equal to static_extent(r) for any r for which static_extent(r) represents a static extent, or
• an element in exts is negative or not representable as a value of type IndexType.

4,5) If N equals rank_dynamic(), for all d in [​0​, rank_dynamic()), direct-non-list-initializes dynamic-extents[d] with std::as_const(exts[d]). Otherwise, for all d in [​0​, rank_dynamic()), direct-non-list-initializes dynamic-extents[d] with std::as_const(exts[dynamic-index-inv(d)]).

• This overload participates in overload resolution only if

• std::is_convertible_v<const OtherIndexType&, IndexType> is true,
• std::is_nothrow_constructible_v<IndexType, const OtherIndexType&> is true, and
• N == rank_dynamic() || N == rank() is true.

• The behavior is undefined if

• N != rank_dynamic() and exts[r] is not equal to static_extent(r) for any r for which static_extent(r) represents a static extent, or
• exts[r] is negative or not representable as a value of type IndexType for any rank index r.

Parameters

other	-	another extents to convert from
exts	-	represents the extents