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86 lines
2.9 KiB
C++
86 lines
2.9 KiB
C++
/*
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Copyright (C) 2010 Apple Inc. All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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1. Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
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EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
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DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
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ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef NullPtr_h
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#define NullPtr_h
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// For compilers and standard libraries that do not yet include it, this adds the
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// nullptr_t type and nullptr object. They are defined in the same namespaces they
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// would be in compiler and library that had the support.
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#if COMPILER_SUPPORTS(CXX_NULLPTR) || defined(_LIBCPP_VERSION)
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// libstdc++ supports nullptr_t starting with gcc 4.6. STLport doesn't define it.
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#if (defined(__GLIBCXX__) && __GLIBCXX__ < 20110325) || defined(_STLPORT_VERSION)
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namespace std {
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typedef decltype(nullptr) nullptr_t;
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}
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#endif
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#else
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#include "wtf/WTFExport.h"
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namespace std {
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class nullptr_t {
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public:
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// Required in order to create const nullptr_t objects without an
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// explicit initializer in GCC 4.5, a la:
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//
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// const std::nullptr_t nullptr;
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nullptr_t() { }
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// Make nullptr convertible to any pointer type.
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template<typename T> operator T*() const { return 0; }
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// Make nullptr convertible to any member pointer type.
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template<typename C, typename T> operator T C::*() { return 0; }
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private:
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// Do not allow taking the address of nullptr.
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void operator&();
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};
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}
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WTF_EXPORT extern const std::nullptr_t nullptr;
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#endif
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#if COMPILER_SUPPORTS(CXX_DELETED_FUNCTIONS)
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#define WTF_DISALLOW_CONSTRUCTION_FROM_ZERO(ClassName) \
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private: \
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ClassName(int) = delete
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#define WTF_DISALLOW_ZERO_ASSIGNMENT(ClassName) \
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private: \
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ClassName& operator=(int) = delete
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#else
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#define WTF_DISALLOW_CONSTRUCTION_FROM_ZERO(ClassName) \
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private: \
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ClassName(int)
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#define WTF_DISALLOW_ZERO_ASSIGNMENT(ClassName) \
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private: \
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ClassName& operator=(int)
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#endif
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#endif
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