single property Null safety

E single

Checks that this iterable has only one element, and returns that element.

Throws a StateError if this is empty or has more than one element.

Implementation

E get single {
  if (_head == _tail) throw IterableElementError.noElement();
  if (length > 1) throw IterableElementError.tooMany();
  return _table[_head] as E;
}