NullPtr.h

/*

Copyright (C) 2010 Apple Inc. All rights reserved.

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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. 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 INC. 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 NullPtr_h
#define NullPtr_h

// For compilers and standard libraries that do not yet include it, this adds the
// nullptr_t type and nullptr object. They are defined in the same namespaces they
// would be in compiler and library that had the support.

#ifndef __has_feature
    #define __has_feature(feature) 0
#endif

#if __has_feature(cxx_nullptr) || (GCC_VERSION_AT_LEAST(4, 6, 0) && defined(__GXX_EXPERIMENTAL_CXX0X__)) || (defined(_MSC_VER) && _MSC_VER >= 1600)

#define HAVE_NULLPTR 1

#else

namespace std {
    class nullptr_t { };
}

extern std::nullptr_t nullptr;

#endif

#endif