Is it possible to implement or use a queue as a data structure in Dart?

Yes, in Dart it is possible to implement and use a queue as a data structure. The standard Dart library includes the Queue class from the dart:collection package, which implements a double-ended queue (deque).

Queue allows efficient addition of elements at the beginning and end, as well as removal from there.

Example of usage:

import 'dart:collection';

void main() {
  Queue<int> queue = Queue<int>();
  queue.addLast(1); // Add to the end
  queue.addLast(2);
  queue.addFirst(0); // Add to the beginning

  print(queue); // (0, 1, 2)

  int first = queue.removeFirst(); // Remove the first element
  print(first); // 0
  print(queue); // (1, 2)
}

Thus, for tasks that require a queue, you can use the built-in Queue class or implement your own structure if necessary.