gecko/xpcom/glue/nsIInterfaceRequestorUtils.h

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/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (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.mozilla.org/MPL/
*
* 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 the Mozilla browser.
*
* The Initial Developer of the Original Code is
* Netscape Communications, Inc.
* Portions created by the Initial Developer are Copyright (C) 1999
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#ifndef __nsInterfaceRequestorUtils_h
#define __nsInterfaceRequestorUtils_h
#include "nsCOMPtr.h"
// a type-safe shortcut for calling the |GetInterface()| member function
// T must inherit from nsIInterfaceRequestor, but the cast may be ambiguous.
template <class T, class DestinationType>
inline
nsresult
CallGetInterface( T* aSource, DestinationType** aDestination )
{
NS_PRECONDITION(aSource, "null parameter");
NS_PRECONDITION(aDestination, "null parameter");
return aSource->GetInterface(NS_GET_TEMPLATE_IID(DestinationType),
NS_REINTERPRET_CAST(void**, aDestination));
}
class NS_COM_GLUE nsGetInterface : public nsCOMPtr_helper
{
public:
nsGetInterface( nsISupports* aSource, nsresult* error )
: mSource(aSource),
mErrorPtr(error)
{
// nothing else to do here
}
virtual nsresult NS_FASTCALL operator()( const nsIID&, void** ) const;
private:
nsISupports* mSource;
nsresult* mErrorPtr;
};
inline
const nsGetInterface
do_GetInterface( nsISupports* aSource, nsresult* error = 0 )
{
return nsGetInterface(aSource, error);
}
#endif // __nsInterfaceRequestorUtils_h