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9d45f08968
This also changes the header to use compiler detection instead of a configure test. This makes the header more portable because it doesn't require the configure infrastructure.
47 lines
1.2 KiB
C++
47 lines
1.2 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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/*
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* Implements a workaround for compilers which do not support the C++11 nullptr
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* constant.
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*/
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#ifndef mozilla_NullPtr_h_
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#define mozilla_NullPtr_h_
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#if defined(__clang__)
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# ifndef __has_extension
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# define __has_extension __has_feature
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# endif
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# if __has_extension(cxx_nullptr)
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# define MOZ_HAVE_CXX11_NULLPTR
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# endif
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#elif defined(__GNUC__)
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# if defined(_GXX_EXPERIMENTAL_CXX0X__) || __cplusplus >= 201103L
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# if (__GNUC__ * 1000 + __GNU_MINOR__) >= 4006
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# define MOZ_HAVE_CXX11_NULLPTR
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# endif
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# endif
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#elif _MSC_VER >= 1600
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# define MOZ_HAVE_CXX11_NULLPTR
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#endif
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/**
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* Use C++11 nullptr if available; otherwise use __null for gcc, or a 0 literal
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* with the correct size to match the size of a pointer on a given platform.
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*/
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#ifndef MOZ_HAVE_CXX11_NULLPTR
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# if defined(__GNUC__)
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# define nullptr __null
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# elif defined(_WIN64)
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# define nullptr 0LL
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# else
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# define nullptr 0L
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# endif
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#endif
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#endif /* mozilla_NullPtr_h_ */
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