70 lines
1.3 KiB
C++
70 lines
1.3 KiB
C++
#ifndef BOOST_CORE_LAUNDER_HPP_INCLUDED
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#define BOOST_CORE_LAUNDER_HPP_INCLUDED
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// MS compatible compilers support #pragma once
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#if defined(_MSC_VER) && (_MSC_VER >= 1020)
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# pragma once
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#endif
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// Copyright 2023 Peter Dimov
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// Distributed under the Boost Software License, Version 1.0.
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// https://www.boost.org/LICENSE_1_0.txt
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#include <boost/config.hpp>
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#if defined(__has_builtin)
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# if __has_builtin(__builtin_launder)
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# define BOOST_CORE_HAS_BUILTIN_LAUNDER
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# endif
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#endif
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#if defined(BOOST_MSVC) && BOOST_MSVC < 1920
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// msvc-14.1 suffers from internal compiler errors when using std::launder
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// https://github.com/boostorg/core/issues/160
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// https://github.com/boostorg/optional/issues/122
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#elif (BOOST_CXX_VERSION >= 201703L) && !defined(BOOST_CORE_HAS_BUILTIN_LAUNDER)
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#include <new>
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#if defined(__cpp_lib_launder)
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# define BOOST_CORE_HAS_STD_LAUNDER
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#endif
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#endif
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namespace boost
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{
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namespace core
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{
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#if defined(BOOST_CORE_HAS_BUILTIN_LAUNDER)
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template<class T> T* launder( T* p )
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{
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return __builtin_launder( p );
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}
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#elif defined(BOOST_CORE_HAS_STD_LAUNDER)
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template<class T> T* launder( T* p )
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{
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return std::launder( p );
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}
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#else
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template<class T> T* launder( T* p )
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{
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return p;
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}
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#endif
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} // namespace core
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} // namespace boost
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#endif // #ifndef BOOST_CORE_LAUNDER_HPP_INCLUDED
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