DataModel_detail::ElementProxy< DVL > Class Template Reference

Proxy for lvalue access to DataVector/DataList elements. More...

#include <ElementProxy.h>

List of all members.

Public Types
typedef ROOT_SELECTION_NS::DataModel_detail::ElementProxy < DVL >::self	self
typedef ElementProxy< DVL >	self
Public Member Functions
	ElementProxy (typename DVL::BaseContainer::iterator i, DVL *container)
	Constructor.
ElementProxy &	operator= (const ElementProxy &rhs)
	Assignment operator, from an Element proxy.
ElementProxy &	operator= (typename DVL::value_type rhs)
	Assignment operator, from a pointer.
	operator typename DVL::value_type const () const
	Conversion to a (const) pointer.
DVL::value_type const	operator-> () const
	Conversion to a (const) pointer.
DVL *	container () const
	Return the container holding the element that this object proxies.
Public Attributes
ROOT_SELECTION_NS::MemberAttributes < kTransient >	m_proxied
ROOT_SELECTION_NS::MemberAttributes < kTransient >	m_container

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Detailed Description

template<class DVL>
class DataModel_detail::ElementProxy< DVL >

Proxy for lvalue access to DataVector/DataList elements.

We need to be careful with lvalue references to DataVector/List elements. If the DataVector/List owns its elements, then if we write into the DataVector/List via an lvalue, the old element should be deleted (and the DataVector/List then takes ownership of the new value). We implement this by having the lvalue references return a proxy object rather than a raw reference. The proxy handles ownership issues. To do this, the proxy stores a pointer to the original container.

When inheritance is used with DataVector/List, we have the additional restriction that we can only write into the DataVector/List using the most-derived DataVector/List class. We also need to enforce that in ElementProxy when there's an attempt to write via an lvalue. We can also get this information from the original container.

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Constructor & Destructor Documentation

template<class DVL >

DataModel_detail::ElementProxy< DVL >::ElementProxy	(	typename DVL::BaseContainer::iterator	i,
		DVL *	container
	)			[inline]

Constructor.

Parameters:

	i	The underlying container iterator pointing at the element which we're proxying.
	container	The container that the iterator references.

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Member Function Documentation

template<class DVL >

DataModel_detail::ElementProxy< DVL >::operator typename DVL::value_type const

(

)

const [inline]

Conversion to a (const) pointer.

We just need to do a cast here.

template<class DVL >

DVL::value_type const DataModel_detail::ElementProxy< DVL >::operator->

(

)

const [inline]

Conversion to a (const) pointer.

We just need to do a cast here.

template<class DVL >

ElementProxy< DVL > & DataModel_detail::ElementProxy< DVL >::operator=

(

typename DVL::value_type

rhs

)

[inline]

Assignment operator, from a pointer.

Parameters:

rhs

The pointer from which we're assigning.

If rhs is the same as the element we're proxying, then we don't need to do anything. Otherwise, can_insert must be true. If the parent DataVector/List owns its elements, we then need to delete the proxied object before making the assignment.

template<class DVL >

ElementProxy< DVL > & DataModel_detail::ElementProxy< DVL >::operator=

(

const ElementProxy< DVL > &

rhs

)

[inline]

Assignment operator, from an Element proxy.

Parameters:

rhs

The proxy from which we're assigning.

If rhs is the same as the element we're proxying, then we don't need to do anything. Otherwise, can_insert must be true. If the parent DataVector/List owns its elements, we then need to delete the proxied object before making the assignment. We also disallow copying between two DataVector/List's, both of which own their elements.

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

• /cvmfs/atlas.cern.ch/repo/sw/ASG/AnalysisBase/2.4.31/AthContainers/AthContainers/tools/ElementProxy.h
• /cvmfs/atlas.cern.ch/repo/sw/ASG/AnalysisBase/2.4.31/AthContainers/AthContainers/tools/ElementProxy.icc