include/comphelper/make_shared_from_uno.hxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19 #ifndef INCLUDED_COMPHELPER_MAKE_SHARED_FROM_UNO_HXX
  20 #define INCLUDED_COMPHELPER_MAKE_SHARED_FROM_UNO_HXX
  21
  22 #include <memory>
  23
  24 namespace comphelper
  25 {
  26 /// @internal
  27 namespace detail
  28 {
  29 /// @internal
  30 template <typename T> struct ReleaseFunc
  31 {
  32     void operator()(T* p) const { p->release(); }
  33 };
  34 } // namespace detail
  35
  36 /** Makes a std::shared_ptr from a ref-counted UNO object pointer.
  37     This makes sense if the object is used via UNO (implementing some X
  38     interface) and also internally using its implementation class, e.g.
  39
  40     <pre>
  41         std::shared_ptr<MyUnoImpl> const ptr(
  42             comphelper::make_shared_from_UNO( new MyUnoImpl ) );
  43         ...
  44         xUno->callingUno( uno::Reference<XSomeInterface>( ptr.get() ) );
  45         ...
  46         takeSharedPtr( ptr );
  47         ...
  48     </pre>
  49
  50     @attention The shared_ptr operates on a separate reference counter, so
  51                weak pointers (std::weak_ptr) are invalidated when the last
  52                shared_ptr is destroyed, although the UNO object may still be
  53                alive.
  54
  55     @param p object pointer
  56     @return shared_ptr to object
  57 */
  58 template <typename T> inline std::shared_ptr<T> make_shared_from_UNO(T* p)
  59 {
  60     p->acquire();
  61     return std::shared_ptr<T>(p, detail::ReleaseFunc<T>());
  62 }
  63
  64 } // namespace comphelper
  65
  66 #endif // ! defined(INCLUDED_COMPHELPER_MAKE_SHARED_FROM_UNO_HXX)
  67
  68 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */