boost::multi::subarray

Mutable D‐dimensional view into part or all of an array

Synopsis

Declared in <boost/multi/array_ref.hpp>

template<
    typename T,
    multi::dimensionality_type D,
    typename ElementPtr = T*,
    class Layout = layout_t<D, std::pointer_traits<ElementPtr>::difference_type>>
class subarray
    : public const_subarray<T, D, ElementPtr, Layout>

Description

Represents a subregion of a larger array without owning the elements. Has reference semantics: cannot be rebound, assignments are deep, and size is immutable. Invalidated if the originating array is destroyed or resized.

Base Classes

Name

Description

const_subarray<T, D, ElementPtr, Layout>

Read‐only D‐dimensional subarray‐reference (view into a subarray)

Type Aliases

Name

Description

const_cursor

Indexable const‐cursor, pointer‐like objects that mutidimensioally indexable (type usually returned by .home() const)

const_iterator

const_pointer

For D == 1 it the pointer type to the elements (as immutables), otherwise it is void

const_reference

Subarray immutable reference after binding first index, multi::const_subarray<T, D ‐ 1, P> or, for D == 1, std::pointer_traits<P>::reference (usually T const&)

cursor

Indexable cursor, pointer‐like objects that mutidimensioally indexable (type usually returned by .home())

decay_type

Associated type that this reference decays to (when true copies are needed)

dimensionality_type

Integer type to store dimensionality information (e.g. 1D, 2D, 3D)

element

Element type (T)

element_const_ptr

Pointer to immutable element type (usually T const*)

element_cref

const‐qualified reference type to an element (usually T const&)

element_move_ptr

Pointer‐like type that produces an moved element (r‐value)

element_ptr

Pointer to element type (usually T*)

element_ref

Reference type to an element (usually T&)

element_type [deprecated]

(deprecated, use element)

extension_type [deprecated]

(deprecated) use extent_type

extent_type

A type to store the extent of an array (the range of valid indices in the leading dimension), returned from .extent().

extents_type

A type that stores the extents of the array or subarray (returned from .extents() and used for array constructors)

index

Type to store an index in the leading dimension

index_range

Type that represents a range of indicies

indices_type

A tuple type that allows storing D indices to locate an element in the array

iterator

layout_type

move_iterator

Iterator in the leading dimension that mark elements as movable

pointer

For D == 1 it the pointer type to the elements, otherwise it is void

reference

Subarray reference after binding first index, multi::subarray<T, D ‐ 1, P> or, for D == 1, std::pointer_traits<P>::reference (usually T&)

size_type

A type to hold the size of an array or subarray (size in the leading dimension) (usually signed)

value_type

Member Functions

Name

Description

subarray [constructor] [deleted]

Constructors

~subarray [destructor]

Destructor

operator= [deleted]

Assignment operators

apply

When evaluated on a tuple object this is equivalent to .operator()(get<0>(tup), get<1>(tup), ...). (The argument type typical has tuple_size<Tuple> == D)

as_const

Returns a const‐element view of the subarray, preventing modification of elements.

back

Returns an immutable reference to the back element.

base

begin

cbase

Returns the base const‐pointer of the array (arithmetic base of the layout, generally the first element)

cbegin

returns an const‐iterator to the beginning

cend

returns an const‐iterator to the end

chunked

produces a subarray of higher dimension by chunking in the leading dimension (if count doesn't divide size, so elements are are left out at the end)

const_array_cast

creates a view of the array with element references with const‐removed

decay

materializes an independent, owning array copy of this view with the associated array‐value type (use unary prefix + as a shortcut)

diagonal

Subarray of lower dimension that represents the main diagonal of a square array

dropped

element_moved

A an array view in which elementes references are r‐values

element_transformed

a view with the elements transformed

elements

returns a random‐access range with all the elements of the array

end

extensions [deprecated]

Deprecated, prefer extents().

extents

Returns the index extensions (structured cartesian product of half‐open ranges) for all dimensions as an extents_type (extents_t<D>), a tuple of D index_extension values each encoding [first, last)]. The result can be passed directly to array constructors or compared for shape equality. Prefer this over the deprecated extensions().

flatted

flattened

front

Returns an immutable reference to the front element.

get_allocator

returns the associated allocator

home

returns a cursor pointing to the top corner element of the array

is_flattable

layout

returns the internal layout information of the array

mbegin