#pragma once

#ifndef TCG_ANY_ITERATOR_H

#define TCG_ANY_ITERATOR_H

#include "base.h"

/*

  \file     any_iterator.h

  \brief    This file contains the implementation of a type-erased iterator

  template class.

  \details  Type erasure is a C++ idiom about allocating an interface

            to an object who is then hidden as the interface's implementation

  detail.

            The cost of using a type-erased object instead of its actual type is

  typically

            measured in a heap access at construction and destruction, and one

  virtual

            function call per method invocation.

            A type-erased iterator can be useful to hide implementation details

  about container

            choices, yet providing an iterator-like interface to access the

  stored data.

*/

#ifndef TCG_RVALUES_SUPPORT

#include <boost config.hpp=""></boost>

#ifdef BOOST_NO_RVALUE_REFERENCES

#define TCG_RVALUES_SUPPORT 0

#else

#define TCG_RVALUES_SUPPORT 1

#endif

#endif

namespace tcg {

//****************************************************************************

//    any_iterator_concept (ie the interface)

//****************************************************************************

template <typename dist="" typename="" val,="" valptr,="" valref,=""></typename>

class any_iterator_concept {

public:

  virtual ~any_iterator_concept() {}

  virtual any_iterator_concept *clone() const = 0;

  virtual ValRef operator*() const  = 0;

  virtual ValPtr operator->() const = 0;

  virtual bool operator==(const any_iterator_concept &other) const = 0;

  virtual bool operator!=(const any_iterator_concept &other) const = 0;

  virtual void operator++() = 0;

  virtual any_iterator_concept *operator++(int) {

    assert(false);

    return 0;

  }

  virtual void operator--() { assert(false); }

  virtual any_iterator_concept *operator--(int) {

    assert(false);

    return 0;

  }

  virtual bool operator<(const any_iterator_concept &) const {

    assert(false);

    return false;

  }

  virtual bool operator>(const any_iterator_concept &) const {

    assert(false);

    return false;

  }

  virtual bool operator<=(const any_iterator_concept &) const {

    assert(false);

    return false;

  }

  virtual bool operator>=(const any_iterator_concept &) const {

    assert(false);

    return false;

  }

  virtual any_iterator_concept *operator+(Dist) const {

    assert(false);

    return 0;

  }

  virtual void operator+=(Dist d) { assert(false); }

  virtual any_iterator_concept *operator-(Dist) const {

    assert(false);

    return 0;

  }

  virtual void operator-=(Dist d) { assert(false); }

  virtual Dist operator-(const any_iterator_concept &) const {

    assert(false);

    return 0;

  }

  virtual ValRef operator[](Dist) const {

    assert(false);

    return *(Val *)0;

  }

};

//****************************************************************************

//    any_iterator_model (ie the concrete interface implementations)

//****************************************************************************

template 

          typename ValPtr, typename Dist>

class any_iterator_model

    : public any_iterator_concept<val, dist="" valptr,="" valref,=""> {</val,>

  typedef any_iterator_concept<val, dist="" valptr,="" valref,=""> any_it_concept;</val,>

public:

  any_iterator_model() : m_it() {}

  any_iterator_model(const It &it) : m_it(it) {}

  any_it_concept *clone() const {

    return new any_iterator_model<it, dist="" iterator_cat,="" val,="" valptr,="" valref,="">(</it,>

        *this);

  }

  ValRef operator*() const { return m_it.operator*(); }

  ValPtr operator->() const { return m_it.operator->(); }

  bool operator==(const any_it_concept &other) const {

    return m_it == static_cast<const &="" any_iterator_model="">(other).m_it;</const>

  }

  bool operator!=(const any_it_concept &other) const {

    return m_it != static_cast<const &="" any_iterator_model="">(other).m_it;</const>

  }

  void operator++() { ++m_it; }

  any_it_concept *operator++(int) {

    return new any_iterator_model<it, dist="" iterator_cat,="" val,="" valptr,="" valref,="">(</it,>

        m_it++);

  }

protected:

  It m_it;

};

template 

          typename Dist>

class any_iterator_model

                         ValPtr, Dist>

    : public any_iterator_model

                                ValPtr, Dist> {

  typedef any_iterator_concept<val, dist="" valptr,="" valref,=""> any_it_concept;</val,>

  using any_iterator_model

                           Dist>::m_it;

public:

  any_iterator_model() {}

  any_iterator_model(const It &it)

      : any_iterator_model

                           Dist>(it) {}

  any_it_concept *clone() const {

    return new any_iterator_model

                                  ValRef, ValPtr, Dist>(*this);

  }

  void operator--() { --m_it; }

  any_it_concept *operator--(int) {

    return new any_iterator_model

                                  ValRef, ValPtr, Dist>(m_it--);

  }

};

template 

          typename Dist>

class any_iterator_model

                         ValPtr, Dist>

    : public any_iterator_model

                                ValRef, ValPtr, Dist> {

  typedef any_iterator_concept<val, dist="" valptr,="" valref,=""> any_it_concept;</val,>

  using any_iterator_model

                           Dist>::m_it;

public:

  any_iterator_model() {}

  any_iterator_model(const It &it)

      : any_iterator_model

                           ValPtr, Dist>(it) {}

  any_it_concept *clone() const {

    return new any_iterator_model

                                  ValRef, ValPtr, Dist>(*this);

  }

  bool operator<(const any_it_concept &other) const {

    return m_it < static_cast<const &="" any_iterator_model="">(other).m_it;</const>

  }

  bool operator>(const any_it_concept &other) const {

    return m_it > static_cast<const &="" any_iterator_model="">(other).m_it;</const>

  }

  bool operator<=(const any_it_concept &other) const {

    return m_it <= static_cast<const &="" any_iterator_model="">(other).m_it;</const>

  }

  bool operator>=(const any_it_concept &other) const {

    return m_it >= static_cast<const &="" any_iterator_model="">(other).m_it;</const>

  }

  any_it_concept *operator+(Dist d) const {

    return new any_iterator_model

                                  ValRef, ValPtr, Dist>(m_it + d);

  }

  void operator+=(Dist d) { m_it += d; }

  any_it_concept *operator-(Dist d) const {

    return new any_iterator_model

                                  ValRef, ValPtr, Dist>(m_it - d);

  }

  void operator-=(Dist d) { m_it -= d; }

  Dist operator-(const any_it_concept &other) const {

    return m_it - static_cast<const &="" any_iterator_model="">(other).m_it;</const>

  }

  ValRef operator[](Dist d) const { return m_it[d]; }

};

//****************************************************************************

//    any_iterator  (ie the wrapper to the interface)

//****************************************************************************

template 

          typename ValRef = Val &, typename ValPtr = Val *,

          typename Dist = std::ptrdiff_t>

class any_iterator

    : public std::iterator<iterator_cat, dist,="" val,="" valptr,="" valref=""> {</iterator_cat,>

  any_iterator_concept<val, dist="" valptr,="" valref,=""> *m_model;</val,>

public:

  any_iterator() : m_model(0) {}

  any_iterator(any_iterator_concept<val, dist="" valptr,="" valref,=""> *model)</val,>

      : m_model(model) {}

  template <typename it=""></typename>

  any_iterator(const It &it)

      : m_model(

            new any_iterator_model<it, dist="" iterator_cat,="" val,="" valptr,="" valref,="">(</it,>

                it)) {}

  any_iterator(const any_iterator &other) : m_model(other.m_model->clone()) {}

  any_iterator &operator=(any_iterator other) {

    swap(*this, other);

    return *this;

  }

  ~any_iterator() { delete m_model; }

  friend void swap(any_iterator &a, any_iterator &b) {

    std::swap(a.m_model, b.m_model);

  }

  ValRef operator*() const { return m_model->operator*(); }

  ValPtr operator->() const { return m_model->operator->(); }

  bool operator==(const any_iterator &other) const {

    return m_model->operator==(*other.m_model);

  }

  bool operator!=(const any_iterator &other) const {

    return m_model->operator!=(*other.m_model);

  }

  any_iterator &operator++() {

    ++*m_model;

    return *this;

  }

  any_iterator operator++(int) { return any_iterator((*m_model)++); }

  any_iterator &operator--() {

    --*m_model;

    return *this;

  }

  any_iterator operator--(int) { return any_iterator((*m_model)--); }

  bool operator<(const any_iterator &other) const {

    return m_model->operator<(*other.m_model);

  }

  bool operator>(const any_iterator &other) const {

    return m_model->operator>(*other.m_model);

  }

  bool operator<=(const any_iterator &other) const {

    return m_model->operator<=(*other.m_model);

  }

  bool operator>=(const any_iterator &other) const {

    return m_model->operator>=(*other.m_model);

  }

  any_iterator operator+(Dist d) const { return any_iterator((*m_model) + d); }

  any_iterator &operator+=(Dist d) {

    (*m_model) += d;

    return *this;

  }

  any_iterator operator-(Dist d) const { return any_iterator((*m_model) - d); }

  any_iterator &operator-=(Dist d) {

    (*m_model) -= d;

    return *this;

  }

  Dist operator-(const any_iterator &other) const {

    return m_model->operator-(*other.m_model);

  }

  ValRef operator[](Dist d) const { return m_model->operator[](d); }

#if (TCG_RVALUES_SUPPORT > 0)

  any_iterator(any_iterator &&other) : m_model(other.m_model) {

    other.m_model = 0;

  }

#endif

};

//-------------------------------------------------------------------------------

template 

          typename Dist>

any_iterator<val, dist="" iterator_cat,="" valptr,="" valref,=""> operator+(</val,>

    Dist d, const any_iterator<val, dist="" iterator_cat,="" valptr,="" valref,=""> &it) {</val,>

  return it + d;

}

//****************************************************************************

//    Additional typedefs to the actual types

//****************************************************************************

template <typename val=""></typename>

struct any_iterator<val, tcg::empty_type=""> {</val,>

  typedef any_iterator<val, std::input_iterator_tag=""> input;</val,>

  typedef any_iterator<val, std::output_iterator_tag=""> output;</val,>

  typedef any_iterator<val, std::forward_iterator_tag=""> forward;</val,>

  typedef any_iterator<val, std::bidirectional_iterator_tag=""> bidirectional;</val,>

  typedef any_iterator<val, std::random_access_iterator_tag=""> random;</val,>

};

template 

          typename Dist = std::ptrdiff_t>

struct any_it {

  typedef any_iterator<val, dist="" std::input_iterator_tag,="" valptr,="" valref,=""></val,>

      input;

  typedef any_iterator<val, dist="" std::output_iterator_tag,="" valptr,="" valref,=""></val,>

      output;

  typedef any_iterator<val, dist="" std::forward_iterator_tag,="" valptr,="" valref,=""></val,>

      forward;

  typedef any_iterator

                       Dist>

      bidirectional;

  typedef any_iterator

                       Dist>

      random;

};

}  // namespace tcg

#endif  // TCG_ANY_ITERATOR_H