I'd like to add a three-integer tuple to a ListBuffer. intuitively, my first try is the code snippet 1, which has a syntax error,according to the compiler. Then, I've tried the snippet 2 and 3, both will work. So could someone explain to me why the code in snippet 1 syntactically wrong. snippet 1 import scala.collection.mutable.ListBuffer val b : ListBuffer[(Int, Int,Int)] = ListBuffer() b += (1,1