Gaudi/Tr/TrackDefaultParticles.h

0001 /***********************************************************************************\
0002 * (c) Copyright 1998-2023 CERN for the benefit of the LHCb and ATLAS collaborations *
0003 *                                                                                   *
0004 * This software is distributed under the terms of the Apache version 2 licence,     *
0005 * copied verbatim in the file "LICENSE".                                            *
0006 *                                                                                   *
0007 * In applying this licence, CERN does not waive the privileges and immunities       *
0008 * granted to it by virtue of its status as an Intergovernmental Organization        *
0009 * or submit itself to any jurisdiction.                                             *
0010 \***********************************************************************************/
0011 #pragma once
0012
0013 #include <GaudiKernel/StatusCode.h>
0014 #include <array>
0015 #include <iomanip>
0016 #include <stdexcept>
0017 #include <stdint.h>
0018
0019 namespace Gaudi {
0020   namespace Tr {
0021     class PID {
0022       enum class validated_pid_t { Electron = 0, Muon, Pion, Kaon, Proton };
0023       static constexpr std::array<double, 5> s_mass = { 0.51099891, 105.65837, 139.57018, 493.677, 938.27203 };
0024
0025       validated_pid_t m_value;
0026
0027       static constexpr validated_pid_t validate( int id ) {
0028         switch ( id ) {
0029         case 11:
0030           return validated_pid_t::Electron;
0031         case 13:
0032           return validated_pid_t::Muon;
0033         case 211:
0034           return validated_pid_t::Pion;
0035         case 321:
0036           return validated_pid_t::Kaon;
0037         case 2212:
0038           return validated_pid_t::Proton;
0039         default:
0040           throw std::runtime_error( "invalid PID" );
0041         }
0042       }
0043
0044     public:
0045       constexpr explicit PID( const int id ) : m_value( validate( id ) ) {}
0046
0047       constexpr explicit PID( validated_pid_t pid ) : m_value( pid ) {}
0048
0049       PID() = default;
0050       // Make the creation of thes PID objects expressive in user code
0051       // by calling Gaudi::Tr::PID::Electron()
0052       static constexpr PID Electron() { return PID{ validated_pid_t::Electron }; }
0053
0054       static constexpr PID Muon() { return PID{ validated_pid_t::Muon }; }
0055
0056       static constexpr PID Pion() { return PID{ validated_pid_t::Pion }; }
0057
0058       static constexpr PID Kaon() { return PID{ validated_pid_t::Kaon }; }
0059
0060       static constexpr PID Proton() { return PID{ validated_pid_t::Proton }; }
0061
0062       // Framwork functions allowing the use of PID inside a property
0063       friend const char* toString( PID pid ) {
0064         switch ( pid.m_value ) {
0065         case validated_pid_t::Electron:
0066           return "Electron";
0067         case validated_pid_t::Muon:
0068           return "Muon";
0069         case validated_pid_t::Pion:
0070           return "Pion";
0071         case validated_pid_t::Kaon:
0072           return "Kaon";
0073         case validated_pid_t::Proton:
0074           return "Proton";
0075         default:
0076           throw std::runtime_error( "Calling toString on invalid PID" );
0077         }
0078       }
0079
0080       friend std::ostream& toStream( const PID& pid, std::ostream& os ) {
0081         return os << std::quoted( toString( pid ), '\'' );
0082       }
0083       friend std::ostream& operator<<( std::ostream& os, const PID& pid ) { return toStream( pid, os ); }
0084
0085       friend StatusCode parse( PID& pid, const std::string& in ) {
0086         for ( PID ref : { Electron(), Muon(), Pion(), Kaon(), Proton() } ) {
0087           if ( in != toString( ref ) ) continue;
0088           pid = ref;
0089           return StatusCode::SUCCESS;
0090         }
0091         return StatusCode::FAILURE;
0092       }
0093       //----------------------------------------------------------
0094
0095       constexpr double mass() const { return s_mass[static_cast<int>( m_value )]; }
0096
0097       constexpr bool isElectron() const { return validated_pid_t::Electron == m_value; }
0098
0099       constexpr bool isMuon() const { return validated_pid_t::Muon == m_value; }
0100
0101       constexpr bool isPion() const { return validated_pid_t::Pion == m_value; }
0102
0103       constexpr bool isKaon() const { return validated_pid_t::Kaon == m_value; }
0104
0105       constexpr bool isProton() const { return validated_pid_t::Proton == m_value; }
0106     };
0107   } // namespace Tr
0108 } // namespace Gaudi