shared_ptr.h

Go to the documentation of this file.

/** @file
 *  @author Bram de Greve (bramz@users.sourceforge.net)
 *  @author Tom De Muer (tomdemuer@users.sourceforge.net)
 *
 *  *** BEGIN LICENSE INFORMATION ***
 *  
 *  The contents of this file are subject to the Common Public Attribution License 
 *  Version 1.0 (the "License"); you may not use this file except in compliance with 
 *  the License. You may obtain a copy of the License at 
 *  http://lass.sourceforge.net/cpal-license. The License is based on the 
 *  Mozilla Public License Version 1.1 but Sections 14 and 15 have been added to cover 
 *  use of software over a computer network and provide for limited attribution for 
 *  the Original Developer. In addition, Exhibit A has been modified to be consistent 
 *  with Exhibit B.
 *  
 *  Software distributed under the License is distributed on an "AS IS" basis, WITHOUT 
 *  WARRANTY OF ANY KIND, either express or implied. See the License for the specific 
 *  language governing rights and limitations under the License.
 *  
 *  The Original Code is LASS - Library of Assembled Shared Sources.
 *  
 *  The Initial Developer of the Original Code is Bram de Greve and Tom De Muer.
 *  The Original Developer is the Initial Developer.
 *  
 *  All portions of the code written by the Initial Developer are:
 *  Copyright (C) 2004-2007 the Initial Developer.
 *  All Rights Reserved.
 *  
 *  Contributor(s):
 *
 *  Alternatively, the contents of this file may be used under the terms of the 
 *  GNU General Public License Version 2 or later (the GPL), in which case the 
 *  provisions of GPL are applicable instead of those above.  If you wish to allow use
 *  of your version of this file only under the terms of the GPL and not to allow 
 *  others to use your version of this file under the CPAL, indicate your decision by 
 *  deleting the provisions above and replace them with the notice and other 
 *  provisions required by the GPL License. If you do not delete the provisions above,
 *  a recipient may use your version of this file under either the CPAL or the GPL.
 *  
 *  *** END LICENSE INFORMATION ***
 */

#ifndef LASS_GUARDIAN_OF_INCLUSION_UTIL_SHARED_PTR_H
#define LASS_GUARDIAN_OF_INCLUSION_UTIL_SHARED_PTR_H

#include "util_common.h"
#include "smart_ptr_policies.h"
#include "../num/safe_bool.h"

namespace lass
{
namespace util
{

template
<
    typename T,
    template <typename, typename> class StoragePolicy = ObjectStorage,
    typename CounterPolicy = DefaultCounter
>
class SharedPtr: public StoragePolicy<T, CounterPolicy>
{
public:

    typedef T TPointee;
    typedef StoragePolicy<T, CounterPolicy> TStoragePolicy;
    typedef CounterPolicy TCounterPolicy;
    typedef typename TStoragePolicy::TStorage TStorage;
    typedef typename TStoragePolicy::TPointer TPointer;
    typedef typename TStoragePolicy::TReference TReference;
    typedef typename TCounterPolicy::TCount TCount;

    template <typename U> struct Rebind
    {
        typedef SharedPtr<T, StoragePolicy, CounterPolicy> Type;
    };

    SharedPtr():
        TStoragePolicy()
    {
    }
    explicit SharedPtr(TPointer p):
        TStoragePolicy(p)
    {
        if (!isEmpty())
        {
            CounterPolicy::init(TStoragePolicy::storage());
        }
    }
    template <typename U> SharedPtr(std::auto_ptr<U>& p):
        TStoragePolicy(p.get())
    {
        if (!isEmpty())
        {
            CounterPolicy::init(TStoragePolicy::storage());
        }
        p.release();
    }
    SharedPtr(const SharedPtr& other):
        TStoragePolicy(other)
    {
        if (!isEmpty())
        {
            CounterPolicy::increment(TStoragePolicy::storage());
        }
    }
    template <typename U> SharedPtr(const SharedPtr<U, StoragePolicy, CounterPolicy>& other):
        TStoragePolicy(other)
    {
        if (!isEmpty())
        {
            CounterPolicy::increment(TStoragePolicy::storage());
        }
    }

    ~SharedPtr()
    {
        if (!isEmpty() && CounterPolicy::decrement(TStoragePolicy::storage()))
        {
            CounterPolicy::dispose(TStoragePolicy::storage());
            TStoragePolicy::dispose();
        }
    }

    SharedPtr& operator=(const SharedPtr& other)
    {
        SharedPtr temp(other);
        swap(temp);
        return *this;
    }

    void reset(TPointer p = 0)
    {
        SharedPtr temp(p);
        swap(temp);
    }
    template <typename U> void reset(std::auto_ptr<U>& p)
    {
        SharedPtr temp(p);
        swap(temp);
    }
    
    void swap(SharedPtr& other)
    {
        TStoragePolicy::swap(other);
    }

    TPointer get() const
    {
        return TStoragePolicy::pointer();
    }
    TPointer operator->() const
    {
        LASS_ASSERT(get());
        return get();
    }
    TReference operator*() const
    {
        LASS_ASSERT(get());
        return *get();
    }
    TReference operator[](size_t i) const
    {
        LASS_ASSERT(get());
        return TStoragePolicy::at(i);
    }

    const TCount count() const
    {
        return isEmpty() ? 0 : TCounterPolicy::count(TStoragePolicy::storage());
    }
    const bool isEmpty() const
    {
        return TStoragePolicy::isNull();
    }
    const bool operator!() const
    {
        return isEmpty();
    }
    operator num::SafeBool() const
    {
        return !isEmpty() ? num::safeTrue : num::safeFalse;
    }

    /** returns reference to storage pointer */
    const TStorage& storage() const
    {
        return TStoragePolicy::storage();
    }
    /** returns reference to storage pointer */
    TStorage& storage()
    {
        return TStoragePolicy::storage();
    }
};

}
}

#endif

// EOF