/data/refman/pasoursint/CMSSW_4_1_8_patch9/src/DataFormats/Common/interface/BaseVectorHolder.h

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#ifndef DataFormats_Common_BaseVectorHolder_h
#define DataFormats_Common_BaseVectorHolder_h
#include "FWCore/Utilities/interface/EDMException.h"
#include "DataFormats/Common/interface/BaseHolder.h"
#include <memory>

namespace edm {
  class ProductID;
  template <typename T> class RefToBase;
  namespace reftobase {
    template <typename T>
    class BaseVectorHolder {
    public:
      typedef size_t       size_type;
      typedef T            element_type;
      typedef RefToBase<T> base_ref_type;
      BaseVectorHolder() {}
      virtual ~BaseVectorHolder() {}
      virtual BaseVectorHolder* clone() const = 0;
      virtual BaseVectorHolder* cloneEmpty() const = 0;
      virtual base_ref_type const at(size_type idx) const = 0;
      virtual bool empty() const = 0;
      
      virtual size_type size() const = 0;
      //virtual size_type capacity() const = 0;
      //virtual void reserve(size_type n) = 0;
      virtual void clear() = 0;
      virtual ProductID id() const = 0;
      virtual EDProductGetter const* productGetter() const = 0;
      void swap(BaseVectorHolder& other) {} // nothing to swap

      // the following structure is public 
      // to allow reflex dictionary to compile
      //    protected:
      struct const_iterator_imp {
        typedef ptrdiff_t difference_type;
        const_iterator_imp() { } 
        virtual ~const_iterator_imp() { }
        virtual const_iterator_imp * clone() const = 0;
        virtual void increase() = 0;
        virtual void decrease() = 0;
        virtual void increase( difference_type d ) = 0;
        virtual void decrease( difference_type d ) = 0;
        virtual bool equal_to( const const_iterator_imp * ) const = 0;
        virtual bool less_than( const const_iterator_imp * ) const = 0;
        virtual void assign( const const_iterator_imp * ) = 0;
        virtual base_ref_type deref() const = 0;
        virtual difference_type difference( const const_iterator_imp * ) const = 0;
      };

      struct const_iterator : public std::iterator <std::random_access_iterator_tag, RefToBase<T> >{
        typedef base_ref_type value_type;
        typedef std::auto_ptr<value_type> pointer;
        typedef std::ptrdiff_t difference_type;

        const_iterator() : i( 0 ) { }
        const_iterator( const_iterator_imp * it ) : i( it ) { }
        const_iterator( const const_iterator & it ) : i( it.isValid() ? it.i->clone() : 0 ) { }
        ~const_iterator() { delete i; }
        const_iterator & operator=( const const_iterator & it ) { 
          if ( isInvalid() ) i = it.i;
          else i->assign( it.i ); 
          return *this; 
        }
        const_iterator& operator++() { 
          throwInvalidReference(isInvalid(), "increment");
          i->increase(); 
          return *this; 
        }
        const_iterator operator++( int ) { 
          throwInvalidReference(isInvalid(), "postincrement");
          const_iterator ci = *this; 
          i->increase(); 
          return ci; 
        }
        const_iterator& operator--() { 
          throwInvalidReference(isInvalid(), "decrement");
          i->decrease(); 
          return *this; 
        }
        const_iterator operator--( int ) { 
          throwInvalidReference(isInvalid(), "postdecrement");
          const_iterator ci = *this; 
          i->decrease(); 
          return ci; 
        }
        difference_type operator-( const const_iterator & o ) const { 
          if ( isInvalid() && o.isInvalid() ) return 0;
          throwInvalidReference(isInvalid() || o.isInvalid(), "compute difference with");
          return i->difference( o.i ); 
        }
        const_iterator operator+( difference_type n ) const { 
          throwInvalidReference(isInvalid(), "compute sum with");
          const_iterator_imp * ii = i->clone(); 
          ii->increase( n );
          return const_iterator( ii ); 
        }
        const_iterator operator-( difference_type n ) const { 
          throwInvalidReference(isInvalid(), "compute difference with");
          const_iterator_imp * ii = i->clone();
          ii->decrease( n );
          return const_iterator( ii ); 
        }
        bool operator<( const const_iterator & o ) const { 
          if ( isInvalid() && o.isInvalid() ) return false;
          throwInvalidReference(isInvalid() || o.isInvalid(), "compute < operator with");
          return i->less_than( o.i ); 
        }
        bool operator==( const const_iterator& ci ) const { 
          if ( isInvalid() && ci.isInvalid() ) return true;
          if ( isInvalid() || ci.isInvalid() ) return false;
          return i->equal_to( ci.i ); 
        }
        bool operator!=( const const_iterator& ci ) const { 
          if ( isInvalid() && ci.isInvalid() ) return false;
          if ( isInvalid() || ci.isInvalid() ) return true;
          return ! i->equal_to( ci.i ); 
        }
        value_type operator * () const { 
          throwInvalidReference(isInvalid(), "dereference");
          return i->deref(); 
        }
        pointer operator->() const { 
          return pointer( new value_type( operator*() ) ); 
        }
        const_iterator & operator +=( difference_type d ) { 
          throwInvalidReference(isInvalid(), "increment");
          i->increase( d ); 
          return *this; 
        }
        const_iterator & operator -=( difference_type d ) { 
          throwInvalidReference(isInvalid(), "decrement");
          i->decrease( d ); 
          return *this; 
        }
        bool isValid() const { return i != 0; }
        bool isInvalid() const { return i == 0; }

        void throwInvalidReference(bool isInvalid, const char *why) const
        {
          if (isInvalid)
          {
            Exception::throwThis(edm::errors::InvalidReference, "Trying to ", why, " an invalid RefToBaseVector<T>::const_iterator");
          }
        }


      private:
        const_iterator_imp * i;
      };

      virtual const_iterator begin() const = 0;
      virtual const_iterator end() const = 0;
      virtual void push_back( const BaseHolder<T> * ) = 0;
      virtual std::auto_ptr<RefVectorHolderBase> vectorHolder() const = 0;
      virtual const void * product() const = 0;

      virtual bool isAvailable() const = 0;

    };

    // Free swap function
    template <typename T>
    inline
    void
    swap(BaseVectorHolder<T>& lhs, BaseVectorHolder<T>& rhs) {
      lhs.swap(rhs);
    }
  }
}

#endif