--- /dev/null
+#ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_GCC_ATOMIC_HPP_INCLUDED
+#define BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_GCC_ATOMIC_HPP_INCLUDED
+
+// boost/detail/atomic_count_gcc_atomic.hpp
+//
+// atomic_count for g++ 4.7+
+//
+// Copyright 2007, 2020 Peter Dimov
+//
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+#include <boost/cstdint.hpp>
+
+#if defined(BOOST_SP_REPORT_IMPLEMENTATION)
+
+#include <boost/config/pragma_message.hpp>
+BOOST_PRAGMA_MESSAGE("Using __atomic atomic_count")
+
+#endif
+
+namespace boost
+{
+
+namespace detail
+{
+
+class atomic_count
+{
+public:
+
+ explicit atomic_count( long v ): value_( static_cast< boost::int_least32_t >( v ) )
+ {
+ }
+
+ long operator++()
+ {
+ return __atomic_add_fetch( &value_, +1, __ATOMIC_ACQ_REL );
+ }
+
+ long operator--()
+ {
+ return __atomic_add_fetch( &value_, -1, __ATOMIC_ACQ_REL );
+ }
+
+ operator long() const
+ {
+ return __atomic_load_n( &value_, __ATOMIC_ACQUIRE );
+ }
+
+private:
+
+ atomic_count(atomic_count const &);
+ atomic_count & operator=(atomic_count const &);
+
+ boost::int_least32_t value_;
+};
+
+} // namespace detail
+
+} // namespace boost
+
+#endif // #ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_GCC_ATOMIC_HPP_INCLUDED