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+#ifndef BOOST_SMART_PTR_DETAIL_LOCAL_COUNTED_BASE_HPP_INCLUDED
+#define BOOST_SMART_PTR_DETAIL_LOCAL_COUNTED_BASE_HPP_INCLUDED
+
+// MS compatible compilers support #pragma once
+
+#if defined(_MSC_VER) && (_MSC_VER >= 1020)
+# pragma once
+#endif
+
+// detail/local_counted_base.hpp
+//
+// Copyright 2017 Peter Dimov
+//
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+//
+// See http://www.boost.org/libs/smart_ptr/ for documentation.
+
+#include <boost/smart_ptr/detail/shared_count.hpp>
+#include <boost/config.hpp>
+#include <utility>
+
+namespace boost
+{
+
+namespace detail
+{
+
+class local_counted_base
+{
+private:
+
+ local_counted_base & operator= ( local_counted_base const & );
+
+private:
+
+ // not 'int' or 'unsigned' to avoid aliasing and enable optimizations
+ enum count_type { min_ = 0, initial_ = 1, max_ = 2147483647 };
+
+ count_type local_use_count_;
+
+public:
+
+ BOOST_CONSTEXPR local_counted_base() BOOST_SP_NOEXCEPT: local_use_count_( initial_ )
+ {
+ }
+
+ BOOST_CONSTEXPR local_counted_base( local_counted_base const & ) BOOST_SP_NOEXCEPT: local_use_count_( initial_ )
+ {
+ }
+
+ virtual ~local_counted_base() /*BOOST_SP_NOEXCEPT*/
+ {
+ }
+
+ virtual void local_cb_destroy() BOOST_SP_NOEXCEPT = 0;
+
+ virtual boost::detail::shared_count local_cb_get_shared_count() const BOOST_SP_NOEXCEPT = 0;
+
+ void add_ref() BOOST_SP_NOEXCEPT
+ {
+#if defined( __has_builtin )
+# if __has_builtin( __builtin_assume )
+
+ __builtin_assume( local_use_count_ >= 1 );
+
+# endif
+#endif
+
+ local_use_count_ = static_cast<count_type>( local_use_count_ + 1 );
+ }
+
+ void release() BOOST_SP_NOEXCEPT
+ {
+ local_use_count_ = static_cast<count_type>( local_use_count_ - 1 );
+
+ if( local_use_count_ == 0 )
+ {
+ local_cb_destroy();
+ }
+ }
+
+ long local_use_count() const BOOST_SP_NOEXCEPT
+ {
+ return local_use_count_;
+ }
+};
+
+class local_counted_impl: public local_counted_base
+{
+private:
+
+ local_counted_impl( local_counted_impl const & );
+
+private:
+
+ shared_count pn_;
+
+public:
+
+ explicit local_counted_impl( shared_count const& pn ): pn_( pn )
+ {
+ }
+
+#if !defined( BOOST_NO_CXX11_RVALUE_REFERENCES )
+
+ explicit local_counted_impl( shared_count && pn ): pn_( std::move(pn) )
+ {
+ }
+
+#endif
+
+ virtual void local_cb_destroy() BOOST_SP_NOEXCEPT
+ {
+ delete this;
+ }
+
+ virtual boost::detail::shared_count local_cb_get_shared_count() const BOOST_SP_NOEXCEPT
+ {
+ return pn_;
+ }
+};
+
+class local_counted_impl_em: public local_counted_base
+{
+public:
+
+ shared_count pn_;
+
+ virtual void local_cb_destroy() BOOST_SP_NOEXCEPT
+ {
+ shared_count().swap( pn_ );
+ }
+
+ virtual boost::detail::shared_count local_cb_get_shared_count() const BOOST_SP_NOEXCEPT
+ {
+ return pn_;
+ }
+};
+
+} // namespace detail
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SMART_PTR_DETAIL_LOCAL_COUNTED_BASE_HPP_INCLUDED