Range.h

/**************************************************************************
 * basf2 (Belle II Analysis Software Framework)                           *
 * Author: The Belle II Collaboration                                     *
 *                                                                        *
 * See git log for contributors and copyright holders.                    *
 * This file is licensed under LGPL-3.0, see LICENSE.md.                  *
 **************************************************************************/
#pragma once
 
#include <tracking/trackFindingCDC/utilities/GetIterator.h>
 
#include <algorithm>
#include <iterator>
#include <utility>
 
namespace Belle2 {
  namespace TrackFindingCDC {
 
    template<class AIterator>
    class Range : public std::pair<AIterator, AIterator> {
 
    private:
      using Super = std::pair<AIterator, AIterator>;
 
    public:
      using Iterator = AIterator;
 
      using iterator = Iterator;
 
      using Reference = typename std::iterator_traits<AIterator>::reference;
 
      using value_type = typename std::iterator_traits<AIterator>::value_type;
 
    public:
      Range() = default;
 
      template<class AOtherIterator>
      explicit Range(const std::pair<AOtherIterator, AOtherIterator>& itPair)
        : Super(AIterator(itPair.first), AIterator(itPair.second))
      {}
 
      template<class Ts, class ItT = GetIterator<Ts>>
      explicit Range(const Ts& ts)
        : Super(AIterator(std::begin(ts)), AIterator(std::end(ts)))
      {}
 
      using Super::Super;
 
      Iterator begin() const
      { return this->first; }
 
      Iterator end() const
      { return this->second; }
 
      bool empty() const
      { return begin() == end(); }
 
      std::size_t size() const
      { return std::distance(begin(), end()); }
 
      Reference front() const
      { return *(begin()); }
 
      Reference back() const
      { return *(end() - 1); }
 
      Reference operator[](std::size_t i) const
      { return *(begin() + i); }
 
      Reference at(std::size_t i) const
      {
        if (not(i < size())) {
          throw std::out_of_range("Range : Requested index " + std::to_string(i) + " is out of bounds.");
        }
        return operator[](i);
      }
 
      bool count(Reference t)
      { return std::count(this->begin(), this->end(), t); }
 
    };
 
    template<class AIterator>
    Range<AIterator> asRange(std::pair<AIterator, AIterator> const& x)
    {
      return Range<AIterator>(x);
    }
 
    template<class AIterator>
    Range<AIterator> asRange(AIterator const& itBegin, AIterator const& itEnd)
    {
      return Range<AIterator>(std::make_pair(itBegin, itEnd));
    }
  }
}