#include <gromacs/math/include/gromacs/math/arrayrefwithpadding.h>

Description

template<typename>
class gmx::ArrayRefWithPadding< typename >

Interface to a C array of T (or part of a std container of T), that includes padding that is suitable for the kinds of SIMD operations GROMACS uses.

High level code e.g. in the force calculation routines need to hold a non-owning view of memory and be able to create ArrayRef objects that view padded or unpadded memory, suitable for the various component routines. This class implements that non-owning view, and the only available functionality refers to its size, and the methods to create such ArrayRef objects.

STL-like interface to a C array of T (or part of a std container of T).

Template Parameters

T	Value type of elements.

This class provides an interface similar to std::vector<T, A>, with the following main differences:

This class does not have its own storage. Instead, it references an existing array of values (either a C-style array or part of an existing std::vector<T, A> or std::array<T>).
It is only possible to modify the values themselves through ArrayRef; it is not possible to add or remove values.
Copying objects of this type is cheap, and the copies behave identically to the original object: the copy references the same set of values.

This class is useful for writing wrappers that expose a view of the internal data stored as a single vector/array, which can be a whole or part of the underlying storage.

Methods in this class do not throw, except where indicated.

Note that due to a Doxygen limitation, the constructor that takes a C array whose size is known at compile time does not appear in the documentation.

To refer to const data of type T, ArrayRef<const T> is used. For both const and non-const std::vector and std::array an ArrayRef view can be created. Attempting to create a non-const ArrayRef of a const vector/array will result in a compiler error in the respective constructor.

For SIMD types there is template specialization available (e.g. ArrayRef<SimdReal>) in gromacs/simd/simd_memory.h which should have the same functionality as much as possible.

Todo:: This class is not complete. There are likely also methods missing (not required for current usage).

Public Types
using	value_type = T
	Type of values stored in the reference.

using	size_type = Index
	Type for representing size of the reference.

using	const_pointer = const T *
	Const pointer to an element.

using	const_iterator = const T *
	Const iterator type to an element.

using	pointer = T *
	Pointer to an element.

using	iterator = T *
	Iterator type to an element.

Public Member Functions
	ArrayRefWithPadding ()
	Constructs an empty reference.

	ArrayRefWithPadding (pointer begin, pointer end, pointer paddedEnd)
	Constructs a reference to a particular range. More...

	ArrayRefWithPadding (const ArrayRefWithPadding &o)
	Copy constructor.

	ArrayRefWithPadding (ArrayRefWithPadding &&o) noexcept
	Move constructor.

template<typename U , typename = std::enable_if_t<std::is_same<value_type, const typename std::remove_reference_t<U>::value_type>::value>>
	ArrayRefWithPadding (U &&o)
	Convenience overload constructor to make an ArrayRefWithPadding<const T> from a non-const one. More...

ArrayRefWithPadding &	operator= (ArrayRefWithPadding const &o)
	Copy assignment operator.

ArrayRefWithPadding &	operator= (ArrayRefWithPadding &&o) noexcept
	Move assignment operator.

size_type	size () const
	Return the size of the view, i.e with the padding.

bool	empty () const
	Whether the reference refers to no memory.

ArrayRef< T >	unpaddedArrayRef ()
	Returns an ArrayRef of elements that does not include the padding region.

ArrayRef< const T >	unpaddedConstArrayRef () const
	Returns an ArrayRef of const elements that does not include the padding region.

ArrayRef< T >	paddedArrayRef ()
	Returns an ArrayRef of elements that does include the padding region.

ArrayRef< const T >	paddedConstArrayRef () const
	Returns an ArrayRef of const elements that does include the padding region.

ArrayRefWithPadding< const T >	constArrayRefWithPadding () const
	Returns an identical ArrayRefWithPadding that refers to const elements.

void	swap (ArrayRefWithPadding< T > &other)
	Swaps referenced memory with the other object. More...

Constructor & Destructor Documentation

template<typename >

gmx::ArrayRefWithPadding< typename >::ArrayRefWithPadding	(	pointer	begin,
		pointer	end,
		pointer	paddedEnd
	)

inline

Constructs a reference to a particular range.

Parameters

[in]	begin	Pointer to the beginning of a range.
[in]	end	Pointer to the end of a range without padding.
[in]	paddedEnd	Pointer to the end of a range including padding.

Passed pointers must remain valid for the lifetime of this object.

template<typename >

template<typename U , typename = std::enable_if_t<std::is_same<value_type, const typename std::remove_reference_t<U>::value_type>::value>>

gmx::ArrayRefWithPadding< typename >::ArrayRefWithPadding ( U && o )

inline

Convenience overload constructor to make an ArrayRefWithPadding<const T> from a non-const one.

Todo:: Use std::is_same_v when CUDA 11 is a requirement.

Member Function Documentation

template<typename >

void gmx::ArrayRefWithPadding< typename >::swap ( ArrayRefWithPadding< T > & other )

inline

Swaps referenced memory with the other object.

The actual memory areas are not modified, only the references are swapped.

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

src/gromacs/gmxlib/nonbonded/nb_free_energy.h
src/gromacs/math/include/gromacs/math/arrayrefwithpadding.h

Description

template<typename> class gmx::ArrayRefWithPadding< typename >

Public Types

Public Member Functions

Constructor & Destructor Documentation

Member Function Documentation

template<typename>
class gmx::ArrayRefWithPadding< typename >