title: Concatenate lists in constant time in scala?
body: <p>In Scala, is there a built-in function or external library for concatenating two lists (or arrays, or vectors, or listbuffers, etc) in constant time? Such an operation would presumably destroy / mutate the two original lists. All the functions I see for concatenating lists run in linear time, as far as I can tell.</p>
  
  <p>Thanks much.</p>