A reference counting pointer with copy-on-write. More...

Public Types
typedef value_type	elt_t
	Type of data pointed to.

Public Member Functions
elt_t *	begin ()
	Retreive the pointer without caring for references (unsafe). More...

const elt_t *	begin () const
	Retreive the pointer without caring for references (unsafe). More...

const elt_t *	begin_const () const
	Retreive the pointer without caring for references (unsafe). More...

const elt_t *	end () const
	Retreive the pointer without caring for references (unsafe). More...

elt_t *	end ()
	Retreive the pointer without caring for references (unsafe). More...

const elt_t *	end_const () const
	Retreive the pointer without caring for references (unsafe). More...

RefPointer< elt_t > &	operator= (const RefPointer< elt_t > &p)
	Copy a pointer increasing the reference count. More...

void	reallocate (size_t new_size)
	Replace the pointer with newly allocated data. More...

size_t	ref_count () const
	Number of references to the internal data.

	RefPointer ()
	Create an empty reference.

	RefPointer (size_t new_size)
	Allocate a pointer of s bytes. More...

	RefPointer (elt_t *data, size_t size, bool owned=true)
	Wrap around the given data.

	RefPointer (const RefPointer< elt_t > &p)
	Copy constructor that increases the reference count. More...

size_t	size () const
	Size of pointed-to data. More...

	~RefPointer ()
	Destructor that deletes no longer reference data. More...

Detailed Description

template<class value_type>
class tensor::RefPointer< value_type >

A reference counting pointer with copy-on-write.

This is a pointer that keeps track of whether the same data is shared by other RefPointer structures. It internally keeps a reference counter to store how many pointers look at the data. When the total number of references drops to zero, it destroys the pointed object.

This allows us to have different parts of the code use the same physical (tensor) data, thus avoiding expensive copy operations. The RefPointer behaves thus similar to pointers, but with internal bookkeeping and easier use.

As soon as you manipulate the data (access it through a non-const pointer), it will be silently and transparently copied to another location if the data is shared with other RefPointers. That is, the data encapsulated by a RefPointer is guaranteed not to be modified through side effects.

Note that pointers returned by the various begin() and end() functions are not reference-counted, so you should not store the returned pointers.

Definition at line 49 of file refcount.h.

Constructor & Destructor Documentation

template<class value_type>

tensor::RefPointer< value_type >::RefPointer ( size_t new_size )

Allocate a pointer of s bytes.

template<class value_type>

tensor::RefPointer< value_type >::RefPointer ( const RefPointer< elt_t > & p )

Copy constructor that increases the reference count.

template<class value_type>

tensor::RefPointer< value_type >::~RefPointer ( )

Destructor that deletes no longer reference data.