_NODISCARD iterator find(const key_type& _Keyval)
        {   // find an element in mutable hash table that matches _Keyval
        return (lower_bound(_Keyval));
        }

    _NODISCARD const_iterator find(const key_type& _Keyval) const
        {   // find an element in nonmutable hash table that matches _Keyval
        return (lower_bound(_Keyval));
        }

    _NODISCARD size_type count(const key_type& _Keyval) const
        {   // count all elements that match _Keyval
        _Paircc _Ans = equal_range(_Keyval);
        return (static_cast<size_type>(_STD distance(_Ans.first, _Ans.second)));
        }

    _NODISCARD iterator lower_bound(const key_type& _Keyval)
        {   // find leftmost not less than _Keyval in mutable hash table
        size_type _Bucket = _Hashval(_Keyval);
        for (_Unchecked_iterator _Where = _Begin(_Bucket);
            _Where != _End(_Bucket); ++_Where)
            if (!_Traitsobj(_Traits::_Kfn(*_Where), _Keyval))
                return (_Traitsobj(_Keyval,
                    _Traits::_Kfn(*_Where)) ? end() : _Make_iter(_Where));
        return (end());
        }