 inserted.        *        *  Complexity similar to that of the range constructor.        */       void       insert(initializer_list<value_type> __l)       { _M_h.insert(__l); }        //@{       /**        *  @brief Erases an element from an %unordered_set.        *  @param  __position  An iterator pointing to the element to be erased.        *  @return An iterator pointing to the element immediately following        *          @a __position prior to the element being erased. If no such        *          element exists, end() is returned.        *        *  This function erases an element, pointed to by the given iterator,        *  from an %unordered_