DataVectorWithAlloc.h File Reference

DataVector using a custom allocator for the elements. More...

#include "AthAllocators/ArenaHeapSTLAllocator.h"
#include "AthAllocators/maybeUnprotect.h"
#include "AthContainers/DataVector.h"
#include "AthContainers/DataVectorWithAllocFwd.h"
#include "AthenaKernel/ClassID_traits.h"
#include "AthContainers/DataVectorWithAlloc.icc"

Include dependency graph for DataVectorWithAlloc.h:

Go to the source code of this file.

Classes
class	DataVectorWithAlloc< DV, ALLOC >
	DataVector using a custom allocator for the elements. More...
class	DataVectorWithAlloc< DV, ALLOC >::UPDeleter
	Internal helper to serve as a deleter for our unique_ptr class. More...
class	DataVectorWithAlloc< DV, ALLOC >::Ptr
	unique_ptr holding an element for this vector. More...
class	DataVectorWithAlloc< DV, ALLOC >::ContainerUniquePtr
	Helper for unique_ptr conversions. More...
class	DataVectorWithAlloc< DV, ALLOC >::HeapDeleter
	Internal helper to delete vector elements. More...
struct	ClassID_traits< DataVectorWithAlloc< DV, ALLOC > >
	Specialize ClassID_traits for DataVectorWithAlloc so that they will be automatically made const when recorded in StoreGate. More...
class	SG::DVLDataVectorWithAllocBucket< DV, ALLOC >
	DataBucket class for DataVectorWithAlloc. More...
struct	SG::DataBucketTrait< DataVectorWithAlloc< DV, ALLOC >, U >
	Metafunction to find the proper DataBucket class for the first template argument. More...
class	SG::BaseInfo< DataVectorWithAlloc< DV, ALLOC > >
	Let the BaseInfo for DataVectorWithAlloc forward to that of the base DataVector. More...

Namespaces
	SG
	Forward declaration.

Functions
template<class DV , class ALLOC >
void	swap (DataVectorWithAlloc< DV, ALLOC > &a, DataVectorWithAlloc< DV, ALLOC > &b)
	See DataVector<T, BASE>::swap(). More...

Detailed Description

DataVector using a custom allocator for the elements.

Author

scott snyder snyde.nosp@m.r@bn.nosp@m.l.gov

Date

Aug, 2021 This is a DataVector that uses a custom allocator to for the elements of the vector. The DataVectorWithAlloc type takes the allocator type as a second template argument. Something satisfying the STL allocator interface should work, as should the Arena*STLAllocator types from AthAllocators. If the second argument is defaulted, then AthenaHeapSTLAllocator is used.

The main difference in usage from an ordinary DataVector is that you need to allocate elements with the allocate() method, rather than using new. This will return a unique_ptr-like type Ptr, which should then be passed to the methods adding an element to the container

using Vec = DataVectorWithAlloc<DataVector<T> >;
Vec v ...;
v.push_back (v.allocate());
Vec::Ptr p = v.allocate (123);
v[0] = std::move (p);

Similarly to ConstDataVector, the DataVector methods that take bare pointers are hidden via private inheritance, and the first template argument is the base DataVector type, or something deriving from it. A DataVectorWithAlloc<DV> may be converted to a const DV using asDataVector, or by recording it in StoreGate. Once recorded, it may be retrieved as a const DV, and it will also act as this for purposes of I/O.

It may be interesting to use the protect() methods of the AthAllocators classes to write-protect the contents of the vector. If that is done, the memory will automatically be unprotected when the vector is destroyed. For this to work, of course, the contents must be really immutable, not just const.

Definition in file DataVectorWithAlloc.h.

Function Documentation

swap()

template<class DV , class ALLOC >

void swap	(	DataVectorWithAlloc< DV, ALLOC > &	a,
		DataVectorWithAlloc< DV, ALLOC > &	b
	)

See DataVector<T, BASE>::swap().

Definition at line 784 of file DataVectorWithAlloc.h.

{
  a.swap (b);
}