EvtSherpaRandom.hh

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#ifdef EVTGEN_SHERPA
 
#ifndef EVTSHERPARANDOM_HH
#define EVTSHERPARANDOM_HH
 
#include "EvtGenBase/EvtRandom.hh"
 
#include "ATOOLS/Math/Random.H"
 
/* Description: Class to specify the chosen EvtGen random number (engine)
 * to be used for Sherpa. 
 */
 
class EvtSherpaRandom : public ATOOLS::External_RNG {
  public:
    double Get() { return EvtRandom::Flat(); }
 
  private:
};
 
// The following code makes EvtSherpaRandom loadable in Sherpa

 
// In Sherpa versions v2.2.15 and earlier the DECLARE_GETTER macro produces code that doesn't compile with gcc versions > 12 and C++20
// So, in those cases, instead use explicit code that has been modified to work correctly
#ifdef EVTGEN_SHERPA_USEMACRO
DECLARE_GETTER( EvtSherpaRandom, "EvtSherpaRandom", ATOOLS::External_RNG,
                ATOOLS::RNG_Key );
#else
namespace ATOOLS {
    template <>
    class Getter<External_RNG, RNG_Key, EvtSherpaRandom> :
        public Getter_Function<External_RNG, RNG_Key> {
      public:
        Getter( const bool& d = true ) :
            Getter_Function<External_RNG, RNG_Key>{ "EvtSherpaRandom" }
        {
            SetDisplay( d );
        }
 
      protected:
        void PrintInfo( std::ostream& str, const size_t width ) const;
        Object_Type* operator()( const Parameter_Type& parameters ) const;
 
      private:
        static Getter<External_RNG, RNG_Key, EvtSherpaRandom> s_initializer;
    };
}    // namespace ATOOLS
 
ATOOLS::Getter<ATOOLS::External_RNG, ATOOLS::RNG_Key, EvtSherpaRandom>
    ATOOLS::Getter<ATOOLS::External_RNG, ATOOLS::RNG_Key, EvtSherpaRandom>::s_initializer{
        true };
#endif
 
ATOOLS::External_RNG*
ATOOLS::Getter<ATOOLS::External_RNG, ATOOLS::RNG_Key, EvtSherpaRandom>::operator()(
    const ATOOLS::RNG_Key& ) const
{
    return new EvtSherpaRandom();
}
 
// This eventually prints a help message
void ATOOLS::Getter<ATOOLS::External_RNG, ATOOLS::RNG_Key, EvtSherpaRandom>::PrintInfo(
    std::ostream& str, const size_t ) const
{
    str << " EvtGen-Sherpa RNG interface";
}

 
#endif
 
#endif