iterator_rdestl.h

#ifndef RDESTL_ITERATOR_H
#define RDESTL_ITERATOR_H

#include <stk_util/util/rdestl_common.h>

namespace rde
{

//-----------------------------------------------------------------------------
struct input_iterator_tag {};
struct output_iterator_tag {};
struct forward_iterator_tag: public input_iterator_tag {};
struct bidirectional_iterator_tag: public forward_iterator_tag {};
struct random_access_iterator_tag: public bidirectional_iterator_tag {};

//-----------------------------------------------------------------------------
template<typename IterT>
struct iterator_traits
{
   typedef typename IterT::iterator_category iterator_category;
};

template<typename T>
struct iterator_traits<T*>
{
   typedef random_access_iterator_tag iterator_category;
};

//-----------------------------------------------------------------------------
namespace internal
{
  template<typename TIter, typename TDist> RDE_FORCEINLINE
  void distance(TIter first, TIter last, TDist& dist, rde::random_access_iterator_tag)
  {
    dist = TDist(last - first);
  }
  template<typename TIter, typename TDist> RDE_FORCEINLINE
  void distance(TIter first, TIter last, TDist& dist, rde::input_iterator_tag)
  {
    dist = 0;
    while (first != last)
    {
      ++dist;
      ++first;
    }
  }

  template<typename TIter, typename TDist> RDE_FORCEINLINE
  void advance(TIter& iter, TDist d, rde::random_access_iterator_tag)
  {
    iter += d;
  }
  template<typename TIter, typename TDist> RDE_FORCEINLINE
  void advance(TIter& iter, TDist d, rde::bidirectional_iterator_tag)
  {
    if (d >= 0)
    {
      while (d--)
        ++iter;
    }
    else
    {
      while (d++)
        --iter;
    }
  }
  template<typename TIter, typename TDist> RDE_FORCEINLINE
  void advance(TIter& iter, TDist d, rde::input_iterator_tag)
  {
    RDE_ASSERT(d >= 0);
    while (d--)
      ++iter;
  }
} // namespace internal
} // namespace rde

//-----------------------------------------------------------------------------
#endif // #ifndef RDESTL_ITERATOR_H