BDSTypeSafeEnum.hh

/* 
Beam Delivery Simulation (BDSIM) Copyright (C) Royal Holloway, 
University of London 2001 - 2022.
 
This file is part of BDSIM.
 
BDSIM is free software: you can redistribute it and/or modify 
it under the terms of the GNU General Public License as published 
by the Free Software Foundation version 3 of the License.
 
BDSIM is distributed in the hope that it will be useful, but 
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
 
You should have received a copy of the GNU General Public License
along with BDSIM.  If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef BDSTYPESAFEENUM_H
#define BDSTYPESAFEENUM_H 
 
#include <map>
#include <ostream>
#include <string>
 
template<typename def, typename inner = typename def::type>
class BDSTypeSafeEnum : public def
{
  typedef inner type;
  inner val;
 
protected:
  // pointer used since static memory possibly doesn't know size of map at creation
  static std::map<BDSTypeSafeEnum<def,inner>,std::string>* dictionary;
  
public:
 
  BDSTypeSafeEnum() : val() {}
  BDSTypeSafeEnum(type v) : val(v) {}
  type underlying() const { return val; }
 
  std::string ToString() const {
    if (dictionary) {return (*dictionary)[val];}
    // if no dictionary defined return empty string
    return "";
  }
  
  friend bool operator == (const BDSTypeSafeEnum & lhs, const BDSTypeSafeEnum & rhs) { return lhs.val == rhs.val; }
  friend bool operator != (const BDSTypeSafeEnum & lhs, const BDSTypeSafeEnum & rhs) { return lhs.val != rhs.val; }
  friend bool operator <  (const BDSTypeSafeEnum & lhs, const BDSTypeSafeEnum & rhs) { return lhs.val <  rhs.val; }
  friend bool operator <= (const BDSTypeSafeEnum & lhs, const BDSTypeSafeEnum & rhs) { return lhs.val <= rhs.val; }
  friend bool operator >  (const BDSTypeSafeEnum & lhs, const BDSTypeSafeEnum & rhs) { return lhs.val >  rhs.val; }
  friend bool operator >= (const BDSTypeSafeEnum & lhs, const BDSTypeSafeEnum & rhs) { return lhs.val >= rhs.val; }
  friend std::ostream& operator<< (std::ostream &out, const BDSTypeSafeEnum& a) {
    if (dictionary) {out << a.ToString();}
    else {out << a.underlying();}
    return out;
  }
};
 
// this seemed to cause a problem, so commented out and every class needs to define its map
// template<typename def, typename inner>
// std::map<BDSTypeSafeEnum<def,inner>,std::string>* BDSTypeSafeEnum<def,inner>::dictionary=nullptr;
 
#endif