RhodeCode

 * purpose.

 *

 */

#ifndef LEMON_BITS_INVALID_H

#define LEMON_BITS_INVALID_H

///\file

///\brief Definition of INVALID.

namespace lemon {

  ///

  /// See \ref INVALID for the usage.

  struct Invalid {

  public:

    bool operator==(Invalid) { return true;  }

    bool operator!=(Invalid) { return false; }

    bool operator< (Invalid) { return false; }

  };

  /// \ref Invalid is a global type that converts to each iterator

  /// in such a way that the value of the target iterator will be invalid.

  //Some people didn't like this:

  //const Invalid &INVALID = *(Invalid *)0;

#ifdef LEMON_ONLY_TEMPLATES

  const Invalid INVALID = Invalid();

#else

  extern const Invalid INVALID;

#endif