Public Types | Public Member Functions | List of all members
blaze::VectorAccessProxy< VT > Class Template Reference

Access proxy for sparse, N-dimensional vectors.The VectorAccessProxy provides safe access to the elements of a non-const sparse vector.
The proxied access to the elements of a sparse vector is necessary since it may be possible that several insertion operations happen in the same statement. The following code illustrates this with two examples by means of the CompressedVector class: More...

#include <VectorAccessProxy.h>

Inherits blaze::Proxy< VectorAccessProxy< VT >, VT::ElementType >.

Public Types

typedef VT::ElementType RepresentedType
 Type of the represented sparse vector element.
 
typedef RepresentedTypeRawReference
 Raw reference to the represented element.
 

Public Member Functions

template<typename T >
const VectorAccessProxy< VT > & operator= (const T &value) const
 Assignment to the accessed sparse vector element. More...
 
template<typename T >
const VectorAccessProxy< VT > & operator+= (const T &value) const
 Addition assignment to the accessed sparse vector element. More...
 
template<typename T >
const VectorAccessProxy< VT > & operator-= (const T &value) const
 Subtraction assignment to the accessed sparse vector element. More...
 
template<typename T >
const VectorAccessProxy< VT > & operator*= (const T &value) const
 Multiplication assignment to the accessed sparse vector element. More...
 
template<typename T >
const VectorAccessProxy< VT > & operator/= (const T &value) const
 Division assignment to the accessed sparse vector element. More...
 
Constructors
 VectorAccessProxy (VT &sv, size_t i)
 Initialization constructor for a VectorAccessProxy. More...
 
 VectorAccessProxy (const VectorAccessProxy &vap)
 The copy constructor for VectorAccessProxy. More...
 
Destructor
 ~VectorAccessProxy ()
 The destructor for VectorAccessProxy.
 
Operators
const VectorAccessProxyoperator= (const VectorAccessProxy &vap) const
 Copy assignment operator for VectorAccessProxy. More...
 
template<typename T >
const VectorAccessProxyoperator= (const T &value) const
 
template<typename T >
const VectorAccessProxyoperator+= (const T &value) const
 
template<typename T >
const VectorAccessProxyoperator-= (const T &value) const
 
template<typename T >
const VectorAccessProxyoperator*= (const T &value) const
 
template<typename T >
const VectorAccessProxyoperator/= (const T &value) const
 
Utility functions
RawReference get () const
 Returning the value of the accessed sparse vector element. More...
 
bool isRestricted () const
 Returns whether the proxy represents a restricted sparse vector element.. More...
 
Conversion operator
 operator RawReference () const
 Conversion to the accessed sparse vector element. More...
 

Private Member Functions

Forbidden operations
void * operator& () const
 Address operator (private & undefined)
 

Private Attributes

Member variables
VT & sv_
 Reference to the accessed sparse vector.
 
size_t i_
 Index of the accessed sparse vector element.
 

Detailed Description

template<typename VT>
class blaze::VectorAccessProxy< VT >

Access proxy for sparse, N-dimensional vectors.

The VectorAccessProxy provides safe access to the elements of a non-const sparse vector.
The proxied access to the elements of a sparse vector is necessary since it may be possible that several insertion operations happen in the same statement. The following code illustrates this with two examples by means of the CompressedVector class:

// Standard usage of the subscript operator to initialize a vector element.
// Only a single vector matrix element is accessed!
a[0] = 1.0;
// Initialization of a vector element via another vector element.
// Two sparse vector accesses in one statement!
a[1] = a[0];
// Multiple accesses to elements of the sparse vector in one statement!
const double result = a[0] + a[2] + a[4];

The problem (especially with the last statement) is that several insertion operations might take place due to the access via the subscript operator. If the subscript operator would return a direct reference to one of the accessed elements, this reference might be invalidated during the evaluation of a subsequent subscript operator, which results in undefined behavior. This class provides the necessary functionality to guarantee a safe access to the sparse vector elements while preserving the intuitive use of the subscript operator.

Constructor & Destructor Documentation

template<typename VT >
blaze::VectorAccessProxy< VT >::VectorAccessProxy ( VT &  sv,
size_t  i 
)
inlineexplicit

Initialization constructor for a VectorAccessProxy.

Parameters
svReference to the accessed sparse vector.
iThe index of the accessed sparse vector element.
template<typename VT >
blaze::VectorAccessProxy< VT >::VectorAccessProxy ( const VectorAccessProxy< VT > &  vap)
inline

The copy constructor for VectorAccessProxy.

Parameters
vapSparse vector access proxy to be copied.

Member Function Documentation

template<typename VT >
VectorAccessProxy< VT >::RawReference blaze::VectorAccessProxy< VT >::get ( ) const
inline

Returning the value of the accessed sparse vector element.

Returns
Direct/raw reference to the accessed sparse vector element.
template<typename VT >
bool blaze::VectorAccessProxy< VT >::isRestricted ( ) const
inline

Returns whether the proxy represents a restricted sparse vector element..

Returns
true in case access to the sparse vector element is restricted, false if not.
template<typename VT >
blaze::VectorAccessProxy< VT >::operator RawReference ( ) const
inline

Conversion to the accessed sparse vector element.

Returns
Direct/raw reference to the accessed sparse vector element.
template<typename VT>
template<typename T >
const VectorAccessProxy<VT>& blaze::VectorAccessProxy< VT >::operator*= ( const T &  value) const
inline

Multiplication assignment to the accessed sparse vector element.

Parameters
valueThe right-hand side value for the multiplication.
Returns
Reference to the assigned access proxy.
template<typename VT>
template<typename T >
const VectorAccessProxy<VT>& blaze::VectorAccessProxy< VT >::operator+= ( const T &  value) const
inline

Addition assignment to the accessed sparse vector element.

Parameters
valueThe right-hand side value to be added to the sparse vector element.
Returns
Reference to the assigned access proxy.
template<typename VT>
template<typename T >
const VectorAccessProxy<VT>& blaze::VectorAccessProxy< VT >::operator-= ( const T &  value) const
inline

Subtraction assignment to the accessed sparse vector element.

Parameters
valueThe right-hand side value to be subtracted from the sparse vector element.
Returns
Reference to the assigned access proxy.
template<typename VT>
template<typename T >
const VectorAccessProxy<VT>& blaze::VectorAccessProxy< VT >::operator/= ( const T &  value) const
inline

Division assignment to the accessed sparse vector element.

Parameters
valueThe right-hand side value for the division.
Returns
Reference to the assigned access proxy.
template<typename VT >
const VectorAccessProxy< VT > & blaze::VectorAccessProxy< VT >::operator= ( const VectorAccessProxy< VT > &  vap) const
inline

Copy assignment operator for VectorAccessProxy.

Parameters
vapSparse vector access proxy to be copied.
Returns
Reference to the assigned access proxy.
template<typename VT>
template<typename T >
const VectorAccessProxy<VT>& blaze::VectorAccessProxy< VT >::operator= ( const T &  value) const
inline

Assignment to the accessed sparse vector element.

Parameters
valueThe new value of the sparse vector element.
Returns
Reference to the assigned access proxy.

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