kamping::Span< T > Class Template Reference

A span modeled after C++20's std::span. More...

#include <span.hpp>

Public Types
using	element_type = T
	Element type; i.e. T.
using	value_type = std::remove_cv_t<T>
	Value type; i.e. T with volatile and const qualifiers removed.
using	size_type = size_t
	The type used for the size of the span.
using	difference_type = std::ptrdiff_t
	The type used for the difference between two elements in the span.
using	pointer = T*
	The type of a pointer to a single elements in the span.
using	const_pointer = T const*
	The type of a const pointer to a single elements in the span.
using	reference = T&
	The type of a reference to a single elements in the span.
using	const_reference = T const&
	The type of a const reference to a single elements in the span.
using	iterator = pointer
	The type of an iterator to a single elements in the span.
using	reverse_iterator
	The type of a reverse iterator to a single elements in the span.

Public Member Functions
constexpr	Span () noexcept
	Default constructor for an empty span. The pointer is set to nullptr and the size to 0.
template<typename It >
constexpr	Span (It first, size_type size)
	Constructor for a span from an iterator of type It and a size.
template<typename It >
constexpr	Span (It first, It last)
	Constructs a span that is a view over the range [first, last); the resulting span has data() == kamping::internal::to_address(first) and size() == last-first.
template<typename Range >
constexpr	Span (Range &&range)
	Constructs a span that is a view over the range range. The resulting span has data() == std::data(range) and size() == std::size().
constexpr pointer	data () const noexcept
	Get access to the underlying memory.
constexpr iterator	begin () const noexcept
	Get iterator pointing to the first element of the span.
constexpr iterator	end () const noexcept
	Get iterator pointing past the last element of the span.
constexpr reverse_iterator	rbegin () const noexcept
	Get a reverse iterator pointing to the first element of the reversed span.
constexpr reverse_iterator	rend () const noexcept
	Get a reverse iterator pointing to the last element of the reversed span.
constexpr reference	front () const noexcept
	Access the first element of the span.
constexpr reference	back () const noexcept
	Access the last element of the span.
constexpr reference	operator[] (size_type idx) const noexcept
	Access the element at index idx.
constexpr size_type	size () const noexcept
	Returns the number of elements in the Span.
constexpr size_type	size_bytes () const noexcept
	Return the number of bytes occupied by the elements in the Span.
constexpr bool	empty () const noexcept
	Check if the Span is empty.
constexpr Span	first (size_type count) const
	Obtain a span that is a view over the first count elements of the span.
constexpr Span	last (size_type count) const
	Obtain a span that is a view over the last count elements of the span.
constexpr Span	subspan (size_type offset, size_type count) const
	Obtain a span that is a view over the span elements in the range [offset, offset + count).

Protected Attributes
pointer	_ptr
	Pointer to the data referred to by Span.
size_type	_size
	Number of elements of type T referred to by Span.

Detailed Description

template<typename T>
class kamping::Span< T >

A span modeled after C++20's std::span.

Since KaMPIng needs to be C++17 compatible and std::span is part of C++20, we need our own implementation of the above-described functionality.

Template Parameters

T	type for which the span is defined.

Member Typedef Documentation

reverse_iterator

template<typename T >

using kamping::Span< T >::reverse_iterator

Initial value:

 
        std::reverse_iterator<iterator>

The type of a reverse iterator to a single elements in the span.

Constructor & Destructor Documentation

Span() [1/3]

template<typename T >

template<typename It >

constexpr kamping::Span< T >::Span ( It first, size_type size )

inlineconstexpr

Constructor for a span from an iterator of type It and a size.

Parameters

first	Iterator pointing to the first element of the span.
size	The number of elements in the span.

Template Parameters

It	The iterator type.

Span() [2/3]

template<typename T >

template<typename It >

constexpr kamping::Span< T >::Span ( It first, It last )

inlineconstexpr

Constructs a span that is a view over the range [first, last); the resulting span has data() == kamping::internal::to_address(first) and size() == last-first.

If [first, last) is not a valid range, or if It does not model a C++20 contiguous iterator, the behavior is undefined. This is analogous to the behavior of std::span.

Parameters

first	begin iterator of the range
last	end iterator of the range

Template Parameters

It	the iterator type.

Span() [3/3]

template<typename T >

template<typename Range >

constexpr kamping::Span< T >::Span ( Range && range )

inlineconstexpr

Constructs a span that is a view over the range range. The resulting span has data() == std::data(range) and size() == std::size().

If range does not model a C++20 contiguous range, the behavior is undefined. This is analogous to the behavior of std::span.

Parameters

range

The range.

Template Parameters

Range

The range type.

Member Function Documentation

begin()

template<typename T >

constexpr iterator kamping::Span< T >::begin ( ) const

inlineconstexprnoexcept

Get iterator pointing to the first element of the span.

Returns

Iterator pointing to the first element of the span.

data()

template<typename T >

constexpr pointer kamping::Span< T >::data ( ) const

inlineconstexprnoexcept

Get access to the underlying memory.

Returns

Pointer to the underlying memory.

empty()

template<typename T >

constexpr bool kamping::Span< T >::empty ( ) const

inlineconstexprnoexcept

Check if the Span is empty.

Returns

true if the Span is empty, false otherwise.

end()

template<typename T >

constexpr iterator kamping::Span< T >::end ( ) const

inlineconstexprnoexcept

Get iterator pointing past the last element of the span.

Returns

Iterator pointing past the last element of the span.

size()

template<typename T >

constexpr size_type kamping::Span< T >::size ( ) const

inlineconstexprnoexcept

Returns the number of elements in the Span.

Returns

Number of elements in the span.

size_bytes()

template<typename T >

constexpr size_type kamping::Span< T >::size_bytes ( ) const

inlineconstexprnoexcept

Return the number of bytes occupied by the elements in the Span.

Returns

The number of elements in the span times the number of bytes per element.

subspan()

template<typename T >

constexpr Span kamping::Span< T >::subspan ( size_type offset, size_type count ) const

inlineconstexpr

Obtain a span that is a view over the span elements in the range [offset, offset + count).

Parameters

offset	The offset of the first element of the span.
count	The number of elements in the span.

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

• include/kamping/span.hpp