EventContextHash.h

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* (c) Copyright 1998-2025 CERN for the benefit of the LHCb and ATLAS collaborations *
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* This software is distributed under the terms of the Apache version 2 licence,     *
* copied verbatim in the file "LICENSE".                                            *
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#pragma once
#include <GaudiKernel/EventContext.h>
 
class EventContextHash {
public:
  size_t hash( const EventContext& ctx ) const {
    size_t en = ctx.evt();
    size_t es = ctx.slot();
    return en ^ ( es + ( en << 6 ) + ( en >> 2 ) );
  }
  bool equal( const EventContext& a, const EventContext& b ) const { return hash( a ) == hash( b ); }
 
  std::size_t operator()( const EventContext& ctx ) const { return hash( ctx ); }
  bool        operator()( const EventContext& ctx, const EventContext& ctxb ) const { return equal( ctx, ctxb ); }
};