Host span, a non-owning view over a contiguous sequence of host-accessible elements. More...

#include <cudf/utilities/span.hpp>

Public Types
using	element_type = typename span_type::element_type
	Element type.

using	value_type = typename span_type::value_type
	Stored value type.

using	size_type = typename span_type::size_type
	Size type.

using	difference_type = typename span_type::difference_type
	std::ptrdiff_t

using	pointer = typename span_type::pointer
	Pointer returned by data()

using	const_pointer = typename span_type::const_pointer
	Pointer returned by data() const.

using	reference = typename span_type::reference
	Reference returned by operator[].

using	const_reference = typename span_type::const_reference
	Const reference to an element.

using	iterator = pointer
	The type of the iterator returned by begin()

Public Member Functions
constexpr CUDF_HOST_DEVICE	host_span (T *data, std::size_t size)
	Constructs a span from a pointer and a size. More...

constexpr CUDF_HOST_DEVICE	host_span (T *data, std::size_t size, bool is_device_accessible)
	Constructor from pointer, size and device-accessibility flag. More...

template<typename C , std::enable_if_t< is_host_span_supported_container< C >::value &&std::is_convertible_v< std::remove_pointer_t< decltype(thrust::raw_pointer_cast(std::declval< C & >().data()))>()[], T()[]> , * = nullptr>
constexpr	host_span (C &in)

template<typename C , std::enable_if_t< is_host_span_supported_container< C >::value &&std::is_convertible_v< std::remove_pointer_t< decltype(thrust::raw_pointer_cast(std::declval< C & >().data()))>()[], T()[]> , * = nullptr>
constexpr	host_span (C const &in)

template<typename OtherT , std::size_t OtherExtent, std::enable_if_t<(Extent==OtherExtent\|\|Extent==dynamic_extent) &&std::is_convertible_v< OtherT()[], T()[]>, void > * = nullptr>
constexpr	host_span (host_span< OtherT, OtherExtent > const &other) noexcept

constexpr reference	operator[] (size_type idx) const
	Returns a reference to the idx-th element of the sequence. More...

constexpr reference	front () const
	Returns a reference to the first element in the span. More...

constexpr reference	back () const
	Returns a reference to the last element in the span. More...

constexpr CUDF_HOST_DEVICE iterator	begin () const noexcept
	Returns an iterator to the first element of the span. More...

constexpr CUDF_HOST_DEVICE iterator	end () const noexcept
	Returns an iterator to the element following the last element of the span. More...

constexpr CUDF_HOST_DEVICE pointer	data () const noexcept
	Returns a pointer to the beginning of the sequence. More...

constexpr CUDF_HOST_DEVICE size_type	size () const noexcept
	Returns the number of elements in the span. More...

constexpr CUDF_HOST_DEVICE size_type	size_bytes () const noexcept
	Returns the size of the sequence in bytes. More...

constexpr CUDF_HOST_DEVICE bool	empty () const noexcept
	Checks if the span is empty. More...

constexpr host_span	first (size_type count) const noexcept
	Obtains a subspan consisting of the first count elements of the sequence. More...

constexpr host_span	last (size_type count) const noexcept
	Obtains a subspan consisting of the last count elements of the sequence. More...

bool	is_device_accessible () const
	Returns whether the data is device accessible (e.g. pinned memory) More...

constexpr CUDF_HOST_DEVICE host_span	subspan (size_type offset, size_type count) const noexcept
	Obtains a span that is a view over the `count` elements of this span starting at offset. More...

constexpr	operator std::span< T > () const noexcept
	Returns a standard span instance. More...

Static Public Attributes
static constexpr std::size_t	extent = span_type::extent
	The extent of the span.

Detailed Description

template<typename T, std::size_t Extent = cudf::dynamic_extent>
struct cudf::host_span< T, Extent >

Host span, a non-owning view over a contiguous sequence of host-accessible elements.

Backed by cuda::std::span, with additional support for constructing from cudf-supported host containers and for tracking whether the underlying memory is device accessible (e.g. pinned memory), which enables copy engine optimizations.

Definition at line 65 of file span.hpp.

Constructor & Destructor Documentation

◆ host_span() [1/5]

template<typename T , std::size_t Extent = cudf::dynamic_extent>

constexpr CUDF_HOST_DEVICE cudf::host_span< T, Extent >::host_span	(	T *	data,
		std::size_t	size
	)

inlineconstexpr

Constructs a span from a pointer and a size.

Note: This needs to be host-device, as it's used by a host-device function in base_2dspan

Parameters

data	Pointer to the first element in the span
size	The number of elements in the span

Definition at line 92 of file span.hpp.

◆ host_span() [2/5]

template<typename T , std::size_t Extent = cudf::dynamic_extent>

constexpr CUDF_HOST_DEVICE cudf::host_span< T, Extent >::host_span	(	T *	data,
		std::size_t	size,
		bool	is_device_accessible
	)

inlineconstexpr

Constructor from pointer, size and device-accessibility flag.

Note: This needs to be host-device, as it's used by a host-device function in base_2dspan

Parameters

data	Pointer to the first element in the span
size	The number of elements in the span
is_device_accessible	Whether the data is device accessible (e.g. pinned memory)

Definition at line 103 of file span.hpp.

◆ host_span() [3/5]

template<typename T , std::size_t Extent = cudf::dynamic_extent>

template<typename C , std::enable_if_t< is_host_span_supported_container< C >::value &&std::is_convertible_v< std::remove_pointer_t< decltype(thrust::raw_pointer_cast(std::declval< C & >().data()))>(*)[], T(*)[]> , * = nullptr>

constexpr cudf::host_span< T, Extent >::host_span ( C & in )

inlineconstexpr

Constructor from container

Parameters

in	The container to construct the span from

Definition at line 117 of file span.hpp.

◆ host_span() [4/5]

template<typename T , std::size_t Extent = cudf::dynamic_extent>

template<typename C , std::enable_if_t< is_host_span_supported_container< C >::value &&std::is_convertible_v< std::remove_pointer_t< decltype(thrust::raw_pointer_cast(std::declval< C & >().data()))>(*)[], T(*)[]> , * = nullptr>

constexpr cudf::host_span< T, Extent >::host_span ( C const & in )

inlineconstexpr

Constructor from const container

Parameters

in	The container to construct the span from

Definition at line 130 of file span.hpp.

◆ host_span() [5/5]

template<typename T , std::size_t Extent = cudf::dynamic_extent>

template<typename OtherT , std::size_t OtherExtent, std::enable_if_t<(Extent==OtherExtent||Extent==dynamic_extent) &&std::is_convertible_v< OtherT(*)[], T(*)[]>, void > * = nullptr>

constexpr cudf::host_span< T, Extent >::host_span ( host_span< OtherT, OtherExtent > const & other )

inlineconstexprnoexcept

Parameters

other The span to copy

Definition at line 141 of file span.hpp.

Member Function Documentation

◆ back()

template<typename T , std::size_t Extent = cudf::dynamic_extent>

constexpr reference cudf::host_span< T, Extent >::back ( ) const

inlineconstexpr

Returns a reference to the last element in the span.

Calling back on an empty span results in undefined behavior.

Returns: Reference to the last element in the span

Definition at line 179 of file span.hpp.

◆ begin()

template<typename T , std::size_t Extent = cudf::dynamic_extent>

constexpr CUDF_HOST_DEVICE iterator cudf::host_span< T, Extent >::begin ( ) const

inlineconstexprnoexcept

Returns an iterator to the first element of the span.

If the span is empty, the returned iterator will be equal to end().

Returns: An iterator to the first element of the span

Definition at line 188 of file span.hpp.

◆ data()

template<typename T , std::size_t Extent = cudf::dynamic_extent>

constexpr CUDF_HOST_DEVICE pointer cudf::host_span< T, Extent >::data ( ) const

inlineconstexprnoexcept

Returns a pointer to the beginning of the sequence.

Returns: A pointer to the first element of the span

Definition at line 205 of file span.hpp.

◆ empty()

template<typename T , std::size_t Extent = cudf::dynamic_extent>

constexpr CUDF_HOST_DEVICE bool cudf::host_span< T, Extent >::empty ( ) const

inlineconstexprnoexcept

Checks if the span is empty.

Returns: True if the span is empty, false otherwise

Definition at line 228 of file span.hpp.

◆ end()

template<typename T , std::size_t Extent = cudf::dynamic_extent>

constexpr CUDF_HOST_DEVICE iterator cudf::host_span< T, Extent >::end ( ) const

inlineconstexprnoexcept

Returns an iterator to the element following the last element of the span.

This element acts as a placeholder; attempting to access it results in undefined behavior.

Returns: An iterator to the element following the last element of the span

Definition at line 196 of file span.hpp.

◆ first()

template<typename T , std::size_t Extent = cudf::dynamic_extent>

constexpr host_span cudf::host_span< T, Extent >::first ( size_type count ) const

inlineconstexprnoexcept

Obtains a subspan consisting of the first count elements of the sequence.

Parameters

count Number of elements from the beginning of this span to put in the subspan.

Returns: A subspan of the first count elements of the sequence

Definition at line 236 of file span.hpp.

◆ front()

template<typename T , std::size_t Extent = cudf::dynamic_extent>

constexpr reference cudf::host_span< T, Extent >::front ( ) const

inlineconstexpr

Returns a reference to the first element in the span.

Calling front on an empty span results in undefined behavior.

Returns: Reference to the first element in the span

Definition at line 170 of file span.hpp.

◆ is_device_accessible()

template<typename T , std::size_t Extent = cudf::dynamic_extent>

bool cudf::host_span< T, Extent >::is_device_accessible ( ) const

inline

Returns whether the data is device accessible (e.g. pinned memory)

Returns: true if the data is device accessible

Definition at line 257 of file span.hpp.

◆ last()

template<typename T , std::size_t Extent = cudf::dynamic_extent>

constexpr host_span cudf::host_span< T, Extent >::last ( size_type count ) const

inlineconstexprnoexcept

Obtains a subspan consisting of the last count elements of the sequence.

Parameters

count Number of elements from the end of this span to put in the subspan

Returns: A subspan of the last count elements of the sequence

Definition at line 247 of file span.hpp.

◆ operator std::span< T >()

template<typename T , std::size_t Extent = cudf::dynamic_extent>

constexpr cudf::host_span< T, Extent >::operator std::span< T > ( ) const

inlineconstexprnoexcept

Returns a standard span instance.

Returns: Standard span instance

Definition at line 277 of file span.hpp.

◆ operator[]()

template<typename T , std::size_t Extent = cudf::dynamic_extent>

constexpr reference cudf::host_span< T, Extent >::operator[] ( size_type idx ) const

inlineconstexpr

Returns a reference to the idx-th element of the sequence.

The behavior is undefined if idx is out of range (i.e., if it is greater than or equal to size()).

Parameters

idx	the index of the element to access

Returns: A reference to the idx-th element of the sequence, i.e., data()[idx]

Definition at line 156 of file span.hpp.

◆ size()

template<typename T , std::size_t Extent = cudf::dynamic_extent>

constexpr CUDF_HOST_DEVICE size_type cudf::host_span< T, Extent >::size ( ) const

inlineconstexprnoexcept

Returns the number of elements in the span.

Returns: The number of elements in the span

Definition at line 212 of file span.hpp.

◆ size_bytes()

template<typename T , std::size_t Extent = cudf::dynamic_extent>

constexpr CUDF_HOST_DEVICE size_type cudf::host_span< T, Extent >::size_bytes ( ) const

inlineconstexprnoexcept

Returns the size of the sequence in bytes.

Returns: The size of the sequence in bytes

Definition at line 218 of file span.hpp.

◆ subspan()

template<typename T , std::size_t Extent = cudf::dynamic_extent>

constexpr CUDF_HOST_DEVICE host_span cudf::host_span< T, Extent >::subspan	(	size_type	offset,
		size_type	count
	)		const

inlineconstexprnoexcept

Obtains a span that is a view over the count elements of this span starting at offset.

Parameters

offset	The offset of the first element in the subspan
count	The number of elements in the subspan

Returns: A subspan of the sequence, of requested count and offset

Definition at line 266 of file span.hpp.

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

cudf/utilities/span.hpp

Public Types

Public Member Functions

Static Public Attributes

Detailed Description

template<typename T, std::size_t Extent = cudf::dynamic_extent> struct cudf::host_span< T, Extent >

Constructor & Destructor Documentation

◆ host_span() [1/5]

◆ host_span() [2/5]

◆ host_span() [3/5]

◆ host_span() [4/5]

◆ host_span() [5/5]

Member Function Documentation

◆ back()

◆ begin()

◆ data()

◆ empty()

◆ end()

◆ first()

◆ front()

◆ is_device_accessible()

◆ last()

◆ operator std::span< T >()

◆ operator[]()

◆ size()

◆ size_bytes()

◆ subspan()

template<typename T, std::size_t Extent = cudf::dynamic_extent>
struct cudf::host_span< T, Extent >