JConversionIterator.hh

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#ifndef __JLANG__JCONVERSIONITERATOR__
#define __JLANG__JCONVERSIONITERATOR__

#include "JLang/JObjectIterator.hh"


/**
 * \author mdejong
 */

namespace JLANG {}
namespace JPP { using namespace JLANG; }

namespace JLANG {

  /**
   * Interface for object iteration with type conversion.
   */
  template<class JInput_t, class JOutput_t>
  class JConversionIterator :
    public JObjectIterator<JOutput_t>
  {
  public:

    typedef typename JObjectIterator<JOutput_t>::pointer_type  pointer_type;

    
    /**
     * Constructor.
     *
     * \param  input      input iterator
     */
    JConversionIterator(JObjectIterator<JInput_t>& input) :
      in(input)
    {}


    /**
     * Check availability of next element.
     *
     * \return            true if the iteration has more elements; else false
     */
    virtual bool hasNext() 
    {
      return in.hasNext();
    }


    /**
     * Get next element.
     *
     * \return            pointer to element
     */
    virtual const pointer_type& next() 
    {
      const JInput_t* p = in.next();

      if (p != NULL)
        ps.reset(new JOutput_t(*p));  // type conversion
      else
        ps.reset(NULL);

      return ps;
    }

  protected:
    JObjectIterator<JInput_t>& in;
  private:
    pointer_type ps;
  };
}

#endif