A smart pointer to an object of a given type in an IProxyDict (such as StoreGateSvc). It d-casts and caches locally the pointed-at object, to speed-up subsequent accesses. It can be reset by the store for asynchronous updates (IOVSvc). More...

#include <WriteHandle.h>

Collaboration diagram for WriteHandle< T >:

Detailed Description

A smart pointer to an object of a given type in an IProxyDict (such as StoreGateSvc). It d-casts and caches locally the pointed-at object, to speed-up subsequent accesses. It can be reset by the store for asynchronous updates (IOVSvc).

SG::WriteHandle<T> can only create new objects in StoreGate; no proxy should already exist. This handle will only return the pointer that has been recorded.

Usage example:

class MyAlg : public AthAlgorithm
{
  SG::WriteHandle<int> m_int;
};
 
MyAlg::MyAlg(...) : ..., m_int("MyIntSgKey") {
   declareProperty("IntHandle",
                   m_int = SG::WriteHandle<int>("MyIntSgKey"),
                   "a handle to an int in StoreGate");
}
 
StatusCode MyAlg::execute()
{
  ATH_CHECK( m_int.record (std::make_unique<int>(42)) );
  ATH_MSG_INFO("int value @[" << m_int.name() << "]="
               << *m_int);
  *m_int += 10;
  ATH_MSG_INFO("int value @[" << m_int.name() << "]="
               << *m_int);
  return StatusCode::SUCCESS;
}

For more information have a look under the package Control/AthenaExamples/AthExHelloWorld

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

StoreGate/StoreGate/WriteHandle.h