Non-owning view of a contiguous buffer as a multidimensional grid. More...

#include <ah-mdspan.H>

Collaboration diagram for Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >:

Public Types
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 = T

using	value_type = std::remove_cv_t< T >

using	index_type = typename extents_type::index_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

Public Member Functions
constexpr	mdspan () noexcept=default
	Empty view: `data_handle() == nullptr`, every extent is 0.

constexpr	mdspan (const mdspan &) noexcept=default

constexpr	mdspan (mdspan &&) noexcept=default

constexpr mdspan &	operator= (const mdspan &) noexcept=default

constexpr mdspan &	operator= (mdspan &&) noexcept=default

template<class OtherT , class OtherAccessor > requires (not std::is_same_v<OtherT, T> and std::is_convertible_v<OtherT ()[], T ()[]>)
constexpr	mdspan (const mdspan< OtherT, Extents, LayoutPolicy, OtherAccessor > &other) noexcept
	Converting constructor: view a non-`const` element type as a `const`-qualified one (`mdspan<T,...>` -> `mdspan<const T,...>`), mirroring how `T` converts to `const T`.

constexpr	mdspan (data_handle_type p, const extents_type &e) noexcept
	View `p` through the shape `e`.

constexpr	mdspan (data_handle_type p, const mapping_type &m) noexcept
	View `p` through an already-built mapping.

constexpr	mdspan (data_handle_type p, const mapping_type &m, const accessor_type &a) noexcept
	View `p` through mapping `m`, reading via accessor `a`.

template<class... IndexTypes> requires (sizeof...(IndexTypes) >= 1 and (std::is_convertible_v<IndexTypes, index_type> and ...))
constexpr	mdspan (data_handle_type p, IndexTypes... exts) noexcept
	View `p` as a grid with the given per-axis sizes.

template<class OtherIndexType > requires std::is_convertible_v<const OtherIndexType &, index_type>
constexpr	mdspan (data_handle_type p, const std::array< OtherIndexType, extents_type::rank_dynamic()> &dyn) noexcept
	View `p` as a grid whose dynamic axes are packed in an array.

constexpr index_type	extent (rank_type r) const noexcept
	Run-time size of axis `r`.

constexpr const extents_type &	extents () const noexcept
	The shape of this view.

constexpr const mapping_type &	mapping () const noexcept
	The index-to-offset mapping (layout + shape) of this view.

constexpr const accessor_type &	accessor () const noexcept
	The element-access policy of this view.

constexpr data_handle_type	data_handle () const noexcept
	Underlying pointer to the first element (`nullptr` for a default-built view).

constexpr data_handle_type	data () const noexcept

constexpr index_type	size () const noexcept
	Total element count: the product of every `extent(r)`.

constexpr bool	empty () const noexcept
	Checks if the view has no elements.

template<class... Indices> requires (sizeof...(Indices) == extents_type::rank())
constexpr reference	operator() (Indices... idxs) const
	Unchecked element access.

template<class... Indices> requires (sizeof...(Indices) == extents_type::rank())
constexpr reference	at (Indices... idxs) const
	Bounds-checked element access.

Static Public Member Functions
static constexpr rank_type	rank () noexcept
	Number of axes (compile-time constant).

Private Attributes
data_handle_type	ptr_ {}

mapping_type	map_ {}

accessor_type	acc_ {}

Detailed Description

template<class T, class Extents, class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>
class Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >

Non-owning view of a contiguous buffer as a multidimensional grid.

See the file-level documentation for the overview, the rationale for operator() over multi-argument operator[], and the bounds-checking policy (operator() is unchecked, .at() is checked).

Template Parameters

T	element type (may be `const`-qualified for a read-only view).
Extents	an `Aleph::extents<IndexType, ...>` (typically `Aleph::dextents<IndexType, Rank>`).
LayoutPolicy	`Aleph::layout_right` (default, row-major) or `Aleph::layout_left` (column-major).
AccessorPolicy	`Aleph::default_accessor<T>` (default).

Thread-safety: Concurrent reads on different cells are safe. Concurrent writes to overlapping cells are not synchronised.

Definition at line 575 of file ah-mdspan.H.

Member Typedef Documentation

◆ accessor_type

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

using Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::accessor_type = AccessorPolicy

Definition at line 580 of file ah-mdspan.H.

◆ data_handle_type

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

using Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::data_handle_type = typename accessor_type::data_handle_type

Definition at line 586 of file ah-mdspan.H.

◆ element_type

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

using Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::element_type = T

Definition at line 582 of file ah-mdspan.H.

◆ extents_type

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

using Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::extents_type = Extents

Definition at line 578 of file ah-mdspan.H.

◆ index_type

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

using Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::index_type = typename extents_type::index_type

Definition at line 584 of file ah-mdspan.H.

◆ layout_type

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

using Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::layout_type = LayoutPolicy

Definition at line 579 of file ah-mdspan.H.

◆ mapping_type

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

using Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::mapping_type = typename layout_type::template mapping<extents_type>

Definition at line 581 of file ah-mdspan.H.

◆ rank_type

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

using Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::rank_type = typename extents_type::rank_type

Definition at line 585 of file ah-mdspan.H.

◆ reference

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

using Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::reference = typename accessor_type::reference

Definition at line 587 of file ah-mdspan.H.

◆ value_type

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

using Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::value_type = std::remove_cv_t<T>

Definition at line 583 of file ah-mdspan.H.

Constructor & Destructor Documentation

◆ mdspan() [1/9]

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

constexpr Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::mdspan ( )

constexprdefaultnoexcept

Empty view: data_handle() == nullptr, every extent is 0.

◆ mdspan() [2/9]

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

constexpr Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::mdspan ( const mdspan< T, Extents, LayoutPolicy, AccessorPolicy > & )

constexprdefaultnoexcept

◆ mdspan() [3/9]

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

constexpr Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::mdspan ( mdspan< T, Extents, LayoutPolicy, AccessorPolicy > && )

constexprdefaultnoexcept

◆ mdspan() [4/9]

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

template<class OtherT , class OtherAccessor >
requires (not std::is_same_v<OtherT, T> and std::is_convertible_v<OtherT (*)[], T (*)[]>)

constexpr Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::mdspan ( const mdspan< OtherT, Extents, LayoutPolicy, OtherAccessor > & other )

inlineconstexprnoexcept

Converting constructor: view a non-const element type as a const-qualified one (mdspan<T,...> -> mdspan<const T,...>), mirroring how T* converts to const T*.

Only participates when OtherT actually converts to T (so this does not become a silent implicit cast between unrelated element types) and the shapes/layouts/accessors match.

Definition at line 613 of file ah-mdspan.H.

◆ mdspan() [5/9]

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

constexpr Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::mdspan	(	data_handle_type	p,
		const extents_type &	e
	)

inlineconstexprnoexcept

View p through the shape e.

Parameters

p	pointer to the first element of the buffer to view.
e	extents object defining the shape.

Definition at line 621 of file ah-mdspan.H.

◆ mdspan() [6/9]

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

constexpr Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::mdspan	(	data_handle_type	p,
		const mapping_type &	m
	)

inlineconstexprnoexcept

View p through an already-built mapping.

Parameters

p	pointer to the first element of the buffer to view.
m	mapping object defining the layout.

Definition at line 629 of file ah-mdspan.H.

◆ mdspan() [7/9]

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

constexpr Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::mdspan	(	data_handle_type	p,
		const mapping_type &	m,
		const accessor_type &	a
	)

inlineconstexprnoexcept

View p through mapping m, reading via accessor a.

Parameters

p	pointer to the first element of the buffer to view.
m	mapping object defining the layout.
a	accessor object defining element access.

Definition at line 638 of file ah-mdspan.H.

◆ mdspan() [8/9]

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

template<class... IndexTypes>
requires (sizeof...(IndexTypes) >= 1 and (std::is_convertible_v<IndexTypes, index_type> and ...))

constexpr Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::mdspan	(	data_handle_type	p,
		IndexTypes...	exts
	)

inlineexplicitconstexprnoexcept

View p as a grid with the given per-axis sizes.

Convenience constructor equivalent to mdspan(p, extents_type(exts...)).

Parameters

p	pointer to the first element of the buffer to view.
exts	one size per dynamic axis of `Extents`, in rank order.

Definition at line 651 of file ah-mdspan.H.

◆ mdspan() [9/9]

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

template<class OtherIndexType >
requires std::is_convertible_v<const OtherIndexType &, index_type>

constexpr Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::mdspan	(	data_handle_type	p,
		const std::array< OtherIndexType, extents_type::rank_dynamic()> &	dyn
	)

inlineconstexprnoexcept

View p as a grid whose dynamic axes are packed in an array.

Convenience constructor equivalent to mdspan(p, extents_type(dyn)). Matches CA::Dense_Cell_Storage::extents_type (a std::array of all per-axis sizes for a fully-dynamic dextents shape), so a lattice's own extents can be forwarded directly without unpacking them.

Definition at line 664 of file ah-mdspan.H.

Member Function Documentation

◆ accessor()

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

constexpr const accessor_type & Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::accessor ( ) const

inlineconstexprnoexcept

The element-access policy of this view.

Definition at line 690 of file ah-mdspan.H.

References Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::acc_.

◆ at()

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

template<class... Indices>
requires (sizeof...(Indices) == extents_type::rank())

constexpr reference Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::at ( Indices... idxs ) const

inlineconstexpr

Bounds-checked element access.

Parameters

idxs	one index per axis, in rank order.

Returns: A reference to the accessed element.

Exceptions

std::out_of_range if any idxs[r] is outside [0, extent(r)).

Definition at line 741 of file ah-mdspan.H.

References Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::acc_, ah_out_of_range_error_if, Aleph::blossom_maximum_cardinality_matching(), Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::extent(), Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::map_, Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::ptr_, r, and Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::rank().

◆ data()

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

constexpr data_handle_type Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::data ( ) const

inlineconstexprnoexcept

Definition at line 696 of file ah-mdspan.H.

References Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::ptr_.

◆ data_handle()

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::data_handle ( ) const

inlineconstexprnoexcept

Underlying pointer to the first element (nullptr for a default-built view).

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

Definition at line 693 of file ah-mdspan.H.

References Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::ptr_.

◆ empty()

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

constexpr bool Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::empty ( ) const

inlineconstexprnoexcept

Checks if the view has no elements.

Returns: true if any axis has extent 0, false otherwise.

Definition at line 710 of file ah-mdspan.H.

References Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::extent(), r, and Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::rank().

◆ extent()

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

constexpr index_type Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::extent ( rank_type r ) const

inlineconstexprnoexcept

Run-time size of axis r.

Parameters

r	The axis to query.

Returns: The extent of the specified axis.

Definition at line 678 of file ah-mdspan.H.

References Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::map_, and r.

Referenced by Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::at(), Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::empty(), and Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::size().

◆ extents()

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

constexpr const extents_type & Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::extents ( ) const

inlineconstexprnoexcept

The shape of this view.

Definition at line 684 of file ah-mdspan.H.

References Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::map_.

◆ mapping()

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

constexpr const mapping_type & Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::mapping ( ) const

inlineconstexprnoexcept

The index-to-offset mapping (layout + shape) of this view.

Definition at line 687 of file ah-mdspan.H.

References Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::map_.

◆ operator()()

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

template<class... Indices>
requires (sizeof...(Indices) == extents_type::rank())

constexpr reference Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::operator() ( Indices... idxs ) const

inlineconstexpr

Unchecked element access.

Parameters

idxs	one index per axis, in rank order.

Returns: A reference to the accessed element.

Warning: Undefined behavior if any idxs[r] is outside [0, extent(r)) — matches std::mdspan::operator[]'s contract exactly. Use at() for a bounds-checked variant.

Definition at line 728 of file ah-mdspan.H.

References Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::acc_, Aleph::blossom_maximum_cardinality_matching(), Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::map_, and Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::ptr_.

◆ operator=() [1/2]

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

constexpr mdspan & Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::operator= ( const mdspan< T, Extents, LayoutPolicy, AccessorPolicy > & )

constexprdefaultnoexcept

◆ operator=() [2/2]

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

constexpr mdspan & Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::operator= ( mdspan< T, Extents, LayoutPolicy, AccessorPolicy > && )

constexprdefaultnoexcept

◆ rank()

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

static constexpr rank_type Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::rank ( )

inlinestaticconstexprnoexcept

Number of axes (compile-time constant).

Returns: The rank of the mdspan.

Definition at line 672 of file ah-mdspan.H.

Referenced by Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::at(), Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::empty(), and Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::size().

◆ size()

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

constexpr index_type Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::size ( ) const

inlineconstexprnoexcept

Total element count: the product of every extent(r).

Definition at line 699 of file ah-mdspan.H.

References Aleph::blossom_maximum_cardinality_matching(), Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::extent(), r, and Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::rank().

Member Data Documentation

◆ acc_

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

accessor_type Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::acc_ {}

private

Definition at line 592 of file ah-mdspan.H.

Referenced by Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::accessor(), Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::at(), and Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::operator()().

◆ map_

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

mapping_type Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::map_ {}

private

Definition at line 591 of file ah-mdspan.H.

Referenced by Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::at(), Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::extent(), Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::extents(), Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::mapping(), and Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::operator()().

◆ ptr_

template<class T , class Extents , class LayoutPolicy = layout_right, class AccessorPolicy = default_accessor<T>>

data_handle_type Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::ptr_ {}

private

Definition at line 590 of file ah-mdspan.H.

Referenced by Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::at(), Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::data(), Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::data_handle(), and Aleph::mdspan< T, Extents, LayoutPolicy, AccessorPolicy >::operator()().

The documentation for this class was generated from the following file:

ah-mdspan.H

Public Types

Public Member Functions

Static Public Member Functions

Private Attributes

Detailed Description

Member Typedef Documentation

◆ accessor_type

◆ data_handle_type

◆ element_type

◆ extents_type

◆ index_type

◆ layout_type

◆ mapping_type

◆ rank_type

◆ reference

◆ value_type

Constructor & Destructor Documentation

◆ mdspan() [1/9]

◆ mdspan() [2/9]

◆ mdspan() [3/9]

◆ mdspan() [4/9]

◆ mdspan() [5/9]

◆ mdspan() [6/9]

◆ mdspan() [7/9]

◆ mdspan() [8/9]

◆ mdspan() [9/9]

Member Function Documentation

◆ accessor()

◆ at()

◆ data()

◆ data_handle()

◆ empty()

◆ extent()

◆ extents()

◆ mapping()

◆ operator()()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ rank()

◆ size()

Member Data Documentation

◆ acc_

◆ map_

◆ ptr_