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author | Steve Block <steveblock@google.com> | 2009-10-08 17:19:54 +0100 |
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committer | Steve Block <steveblock@google.com> | 2009-10-20 00:41:58 +0100 |
commit | 231d4e3152a9c27a73b6ac7badbe6be673aa3ddf (patch) | |
tree | a6c7e2d6cd7bfa7011cc39abbb436142d7a4a7c8 /JavaScriptCore/wtf/PossiblyNull.h | |
parent | e196732677050bd463301566a68a643b6d14b907 (diff) | |
download | external_webkit-231d4e3152a9c27a73b6ac7badbe6be673aa3ddf.zip external_webkit-231d4e3152a9c27a73b6ac7badbe6be673aa3ddf.tar.gz external_webkit-231d4e3152a9c27a73b6ac7badbe6be673aa3ddf.tar.bz2 |
Merge webkit.org at R49305 : Automatic merge by git.
Change-Id: I8968561bc1bfd72b8923b7118d3728579c6dbcc7
Diffstat (limited to 'JavaScriptCore/wtf/PossiblyNull.h')
-rw-r--r-- | JavaScriptCore/wtf/PossiblyNull.h | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/JavaScriptCore/wtf/PossiblyNull.h b/JavaScriptCore/wtf/PossiblyNull.h new file mode 100644 index 0000000..79c4d82 --- /dev/null +++ b/JavaScriptCore/wtf/PossiblyNull.h @@ -0,0 +1,59 @@ +/* + * Copyright (C) 2009 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. + * + * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 INC. OR + * 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 PossiblyNull_h +#define PossiblyNull_h + +#include "Assertions.h" + +namespace WTF { + +template <typename T> struct PossiblyNull { + PossiblyNull(T data) + : m_data(data) + { + } + PossiblyNull(const PossiblyNull<T>& source) + : m_data(source.m_data) + { + source.m_data = 0; + } + ~PossiblyNull() { ASSERT(!m_data); } + bool getValue(T& out) WARN_UNUSED_RETURN; +private: + mutable T m_data; +}; + +template <typename T> bool PossiblyNull<T>::getValue(T& out) +{ + out = m_data; + bool result = !!m_data; + m_data = 0; + return result; +} + +} + +#endif |