xref: /AOO42X/main/comphelper/inc/comphelper/make_shared_from_uno.hxx (revision 9bce9b0d387299c68bd81d539e1478357a103de5)

/**************************************************************
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
 *************************************************************/


#if ! defined(INCLUDED_COMPHELPER_MAKE_SHARED_FROM_UNO_HXX)
#define INCLUDED_COMPHELPER_MAKE_SHARED_FROM_UNO_HXX

#include "boost/shared_ptr.hpp"
#include <functional>

namespace comphelper {

/// @internal
namespace detail {
/// @internal
template <typename T> struct ReleaseFunc : ::std::unary_function<T *, void> {
    void operator()( T * p ) const { p->release(); }
};
} // namespace detail

/** Makes a boost::shared_ptr from a ref-counted UNO object pointer.
    This makes sense if the object is used via UNO (implementing some X
    interface) and also internally using its implementation class, e.g.

    <pre>
        boost::shared_ptr<MyUnoImpl> const ptr(
            comphelper::make_shared_from_UNO( new MyUnoImpl ) );
        ...
        xUno->callingUno( uno::Reference<XSomeInterface>( ptr.get() ) );
        ...
        takeSharedPtr( ptr );
        ...
    </pre>

    @attention The shared_ptr operates on a separate reference counter, so
               weak pointers (boost::weak_ptr) are invalidated when the last
               shared_ptr is destroyed, although the UNO object may still be
               alive.

    @param p object pointer
    @return shared_ptr to object
*/
template <typename T>
inline ::boost::shared_ptr<T> make_shared_from_UNO( T * p )
{
    p->acquire();
    return ::boost::shared_ptr<T>( p, detail::ReleaseFunc<T>() );
}

} // namespace comphelper

#endif // ! defined(INCLUDED_COMPHELPER_MAKE_SHARED_FROM_UNO_HXX)