root/trunk/whisperlib/common/io/iomarker.h

// Copyright (c) 2009, Whispersoft s.r.l.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Whispersoft s.r.l. nor the names of its
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// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// Author: Catalin Popescu
//
// A base class for providing stream marking
//
#ifndef __COMMON_IO_IOMARKER_H__
#define __COMMON_IO_IOMARKER_H__

namespace io {

class IoMarker {
 public:
  IoMarker() {
  }
  virtual ~IoMarker() {
  }

  // Sets the marker in the current stream possition
  virtual void Set() = 0;
  // Returns true iff the some marker is set
  virtual bool IsSet() const = 0;
  // Restores the position of the associated stream to the position
  // previously marked by set.
  virtual void Restore() = 0;
  // Removes the last mark for the underlying stream
  virtual void Clear() = 0;
 private:
  DISALLOW_EVIL_CONSTRUCTORS(IoMarker);
};
}

#endif  // __COMMON_IO_IOMARKER_H__