+template <class T> typename tools::promote_args_permissive<T>::type (changesign)(const T& x)
+{ //!< \brief return unchanged binary pattern of x, except for change of sign bit.
+ typedef typename detail::fp_traits<T>::sign_change_type traits;
+ typedef typename traits::method method;
+ // typedef typename boost::is_floating_point<T>::type fp_tag;
+ typedef typename tools::promote_args_permissive<T>::type result_type;
+
+ return detail::changesign_impl(static_cast<result_type>(x), method());
+}
+
+template <class T, class U>
+inline typename tools::promote_args_permissive<T, U>::type
+ copysign BOOST_NO_MACRO_EXPAND(const T& x, const U& y)