[apple/javascriptcore.git] / wtf / PassTraits.h

/*
 * Copyright (C) 2011 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1.  Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 * 2.  Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
 *     its contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef WTF_PassTraits_h
#define WTF_PassTraits_h

#include "OwnPtr.h"
#include "RefPtr.h"

// The PassTraits template exists to help optimize (or make possible) use
// of WTF data structures with WTF smart pointers that have a Pass
// variant for transfer of ownership

namespace WTF {

template<typename T> struct PassTraits {
    typedef T Type;
    typedef T PassType;
    static PassType transfer(Type& value) { return value; }
};

template<typename T> struct PassTraits<OwnPtr<T> > {
    typedef OwnPtr<T> Type;
    typedef PassOwnPtr<T> PassType;
    static PassType transfer(Type& value) { return value.release(); }
};

template<typename T> struct PassTraits<RefPtr<T> > {
    typedef RefPtr<T> Type;
    typedef PassRefPtr<T> PassType;
    static PassType transfer(Type& value) { return value.release(); }
};

} // namespace WTF

using WTF::PassTraits;

#endif // WTF_PassTraits_h
Commit	Line	Data
14957cd0 A	1	/*
	2	* Copyright (C) 2011 Apple Inc. All rights reserved.
	3	*
	4	* Redistribution and use in source and binary forms, with or without
	5	* modification, are permitted provided that the following conditions
	6	* are met:
	7	*
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of
	14	* its contributors may be used to endorse or promote products derived
	15	* from this software without specific prior written permission.
	16	*
	17	* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
	18	* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
	19	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	20	* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
	21	* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
	22	* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
	23	* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
	24	* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	27	*/
	28
	29	#ifndef WTF_PassTraits_h
	30	#define WTF_PassTraits_h
	31
	32	#include "OwnPtr.h"
	33	#include "RefPtr.h"
	34
	35	// The PassTraits template exists to help optimize (or make possible) use
	36	// of WTF data structures with WTF smart pointers that have a Pass
	37	// variant for transfer of ownership
	38
	39	namespace WTF {
	40
	41	template<typename T> struct PassTraits {
	42	typedef T Type;
	43	typedef T PassType;
	44	static PassType transfer(Type& value) { return value; }
	45	};
	46
	47	template<typename T> struct PassTraits<OwnPtr<T> > {
	48	typedef OwnPtr<T> Type;
	49	typedef PassOwnPtr<T> PassType;
	50	static PassType transfer(Type& value) { return value.release(); }
	51	};
	52
	53	template<typename T> struct PassTraits<RefPtr<T> > {
	54	typedef RefPtr<T> Type;
	55	typedef PassRefPtr<T> PassType;
	56	static PassType transfer(Type& value) { return value.release(); }
	57	};
	58
	59	} // namespace WTF
	60
	61	using WTF::PassTraits;
	62
	63	#endif // WTF_PassTraits_h