MultiIndexIterator.h

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// Copyright András Vukics 2006–2014. Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE.txt)
// -*- C++ -*-
#ifndef CPPQEDCORE_UTILS_MULTIINDEXITERATOR_H_INCLUDED
#define CPPQEDCORE_UTILS_MULTIINDEXITERATOR_H_INCLUDED

#include "MultiIndexIteratorFwd.h"

#include "BlitzTiny.h"

#include <boost/operators.hpp>

#include <boost/mpl/identity.hpp>


namespace cpputils {


namespace mii {
 
typedef boost::mpl::false_ Begin; 
typedef boost::mpl::true_  End  ;
  
const Begin begin=Begin();
const End   end  =End  ();
  
}


#define FORWARD_IteratorHelper boost::forward_iterator_helper<MultiIndexIterator<RANK>,IdxTiny<RANK> >


template<int RANK>
class MultiIndexIterator : public FORWARD_IteratorHelper
{
private:
  typedef FORWARD_IteratorHelper Base;
  
#undef FORWARD_IteratorHelper

public:
  typedef typename Base::value_type MultiIndex;
  typedef typename MultiIndex::T_numtype SingleIndex;


  MultiIndexIterator(const MultiIndex& lbound, 
                     const MultiIndex& ubound, 
                     mii::Begin)
    : lbound_(lbound), ubound_(ubound), idx_(lbound_) {}

  MultiIndexIterator(const MultiIndex& lbound, const MultiIndex& ubound, mii::End  )
    : lbound_(lbound), ubound_(ubound), idx_(ubound_) {operator++();} 


  MultiIndexIterator(const MultiIndex& ubound, 
                     mii::Begin b)
    : MultiIndexIterator(MultiIndex(SingleIndex(0)),ubound,b) {}


  MultiIndexIterator(const MultiIndex& ubound, mii::End e)
    : MultiIndexIterator(MultiIndex(SingleIndex(0)),ubound,e) {}
  
  MultiIndexIterator& operator=(const MultiIndexIterator& other) {idx_=other.idx_; return *this;}
  

  MultiIndexIterator& operator++() {doIt(boost::mpl::int_<RANK-1>()); return *this;}

  const MultiIndex& operator*() const {return idx_;}
        MultiIndex& operator*()       {return const_cast<MultiIndex&>(static_cast<const MultiIndexIterator*>(this)->operator*());}

  friend bool operator==(const MultiIndexIterator& i1, const MultiIndexIterator& i2) {return all(i1.idx_==i2.idx_);}


  const MultiIndexIterator getBegin() const {return MultiIndexIterator(lbound_,ubound_,mii::begin);}
  const MultiIndexIterator getEnd  () const {return MultiIndexIterator(lbound_,ubound_,mii::end  );}
  
  MultiIndexIterator& setToBegin() {idx_=lbound_; return    *this ;}
  MultiIndexIterator& setToEnd  () {idx_=ubound_; return ++(*this);}
  
private:
  void doIt(boost::mpl::int_<0>);

  template<int N>
  void doIt(boost::mpl::int_<N>);

  const MultiIndex lbound_, ubound_;

  MultiIndex idx_;

};


} // cpputils



#endif // CPPQEDCORE_UTILS_MULTIINDEXITERATOR_H_INCLUDED