JForwardIterator.hh

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#ifndef __JLANG__JFORWARDITERATOR__
#define __JLANG__JFORWARDITERATOR__
 
#include <cstddef>
 
/**
 * \author mdejong
 */
 
namespace JLANG {}
namespace JPP { using namespace JLANG; }
 
namespace JLANG {
 
  /**
   * Template interface for method bool increment().
   * This interface implements the pre-fix and post-fix operators <tt>++</tt>.
   */
  template<class T> 
  class JForwardIterator {
  public:
    /**
     * Virtual destructor.
     */
    virtual ~JForwardIterator()
    {}
 
    
    /**
     * Increment iterator.
     *
     * \return                 this iterator
     */
    T& operator++()
    {
      this->increment();
      
      return static_cast<T&>(*this);
    }
 
 
    /**
     * Increment iterator.
     *
     * \return                 previous iterator
     */
    T operator++(int)
    {
      const T tmp(static_cast<const T&>(*this));
 
      this->increment();
 
      return tmp;
    }
 
 
    /**
     * Advance iterator.
     *
     * \param  offset          offset
     * \return                 iterator
     */
    T& operator+=(const size_t offset)
    {
      this->increment(offset);
 
      return static_cast<T&>(*this);
    }
 
 
    /**
     * Advance operator.
     *
     * \param  object          iterator
     * \param  offset          offset
     * \return                 iterator
     */
    friend inline T operator+(const T& object, const size_t offset)
    {
      T tmp(object);
 
      tmp.increment(offset);
 
      return tmp;
    }
    
 
    /**
     * Increment iterator.
     *
     * \return                 true if incremented; else false
     */
    virtual bool increment() = 0;
 
 
    /**
     * Increment iterator.
     *
     * \param  offset          offset
     * \return                 true if incremented; else false
     */
    virtual bool increment(const size_t offset)
    {
      size_t i = 0;
 
      while (i != offset && this->increment()) {
        ++i;
      }
 
      return i == offset;
    }
  };
}
 
#endif