Decays removed from SFINAE (fixes #22).

include/unique_resource.h

             return m_resource;
         }
 
-        template<class R = std::decay_t<Ressource>,
+        template<class R = Ressource,
             std::enable_if_t<std::is_pointer<R>::value &&
                 ( std::is_class<std::remove_pointer_t<R>>::value
                     || std::is_union<std::remove_pointer_t<R>>::value ), int> = 0>
             return m_resource;
         }
 
-        template<class R = std::decay_t<Ressource>,
+        template<class R = Ressource,
             std::enable_if_t<std::is_pointer<R>::value, int> = 0>
         std::add_lvalue_reference_t<std::remove_pointer_t<Ressource>> operator*() const noexcept
         {