Sans Pareil Technologies, Inc.

/*
 * RefCountedObject.h
 *
 * Definition of the RefCountedObject class.
 *
 * Copyright (c) 2004-2009, Applied Informatics Software Engineering GmbH.
 * and Contributors.
 *
 * Permission is hereby granted, free of charge, to any person or organization
 * obtaining a copy of the software and accompanying documentation covered by
 * this license (the "Software") to use, reproduce, display, distribute,
 * execute, and transmit the Software, and to prepare derivative works of the
 * Software, and to permit third-parties to whom the Software is furnished to
 * do so, all subject to the following:
 *
 * The copyright notices in the Software and this entire statement, including
 * the above license grant, this restriction and the following disclaimer,
 * must be included in all copies of the Software, in whole or in part, and
 * all derivative works of the Software, unless such copies or derivative
 * works are solely in the form of machine-executable object code generated by
 * a source language processor.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
 * SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
 * FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
*/

#ifndef SPT_REFCOUNTEDOBJECT
#define SPT_REFCOUNTEDOBJECT


namespace spt
{
  /// A base class for objects that employ
  /// reference counting based garbage collection.
  ///
  /// Reference-counted objects inhibit construction
  /// by copying and assignment.
  class RefCountedObject
  {
  public:
    /// Creates the RefCountedObject.
    /// The initial reference count is one.
    RefCountedObject() : refcount( 1 ) {}

    /// Increments the object's reference count.
    void duplicate() const { ++refcount; }

    /// Decrements the object's reference count
    /// and deletes the object if the count
    /// reaches zero.
    void release() const;

    /// Returns the reference count.
    int referenceCount() const { return refcount; }

  protected:
    /// Destroys the RefCountedObject.
    virtual ~RefCountedObject() {}

  private:
    RefCountedObject( const RefCountedObject& );
    RefCountedObject& operator = ( const RefCountedObject& );

    mutable uint8_t refcount;
  };


  inline void RefCountedObject::release() const
  {
    if  ( --refcount == 0 ) delete this;
  }

} // namespace spt


#endif // SPT_REFCOUNTEDOBJECT