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+#ifndef BOOST_TYPE_TRAITS_IS_NOTHROW_SWAPPABLE_HPP_INCLUDED
+#define BOOST_TYPE_TRAITS_IS_NOTHROW_SWAPPABLE_HPP_INCLUDED
+
+// 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
+
+#include <boost/config.hpp>
+#include <boost/config/workaround.hpp>
+
+#if defined(BOOST_NO_SFINAE_EXPR) || defined(BOOST_NO_CXX11_NOEXCEPT) || defined(BOOST_NO_CXX11_DECLTYPE) \
+ || defined(BOOST_NO_CXX11_FUNCTION_TEMPLATE_DEFAULT_ARGS) || BOOST_WORKAROUND(BOOST_GCC, < 40700)
+
+#include <boost/type_traits/is_scalar.hpp>
+#include <boost/type_traits/is_const.hpp>
+#include <boost/type_traits/integral_constant.hpp>
+
+namespace boost
+{
+template <class T> struct is_nothrow_swappable : boost::integral_constant<bool,
+ boost::is_scalar<T>::value && !boost::is_const<T>::value> {};
+
+template <class T, class U> struct is_nothrow_swappable_with : false_type {};
+template <class T> struct is_nothrow_swappable_with<T, T> : is_nothrow_swappable<T> {};
+}
+
+#else
+
+#include <boost/type_traits/declval.hpp>
+#include <boost/type_traits/integral_constant.hpp>
+#include <algorithm>
+
+namespace boost
+{
+
+namespace type_traits_swappable_detail
+{
+
+using std::swap;
+
+template<class T, class U, bool B = noexcept(swap(declval<T>(), declval<U>()))> integral_constant<bool, B> is_nothrow_swappable_with_impl( int );
+template<class T, class U> false_type is_nothrow_swappable_with_impl( ... );
+template<class T, class U>
+struct is_nothrow_swappable_with_helper { typedef decltype( type_traits_swappable_detail::is_nothrow_swappable_with_impl<T, U>(0) ) type; };
+
+template<class T, bool B = noexcept(swap(declval<T&>(), declval<T&>()))> integral_constant<bool, B> is_nothrow_swappable_impl( int );
+template<class T> false_type is_nothrow_swappable_impl( ... );
+template<class T>
+struct is_nothrow_swappable_helper { typedef decltype( type_traits_swappable_detail::is_nothrow_swappable_impl<T>(0) ) type; };
+
+} // namespace type_traits_swappable_detail
+
+template<class T, class U> struct is_nothrow_swappable_with: type_traits_swappable_detail::is_nothrow_swappable_with_helper<T, U>::type
+{
+};
+
+template<class T> struct is_nothrow_swappable: type_traits_swappable_detail::is_nothrow_swappable_helper<T>::type
+{
+};
+
+} // namespace boost
+
+#endif
+
+#endif // #ifndef BOOST_TYPE_TRAITS_IS_NOTHROW_SWAPPABLE_HPP_INCLUDED