Question

Suppose I’m only removing a single element. I would like these methods to implement a fixed size ListBuffer. I would only use if they run in O(1) time. The documentation is slightly ambiguous does anybody know the implementation details?

Answer 1

The relevant implementation is there (for ListBuffer) and there (for BufferLike).

trimStart(n) is linear with respect to n (so, constant if you remove a single element); trimEnd(n) is linear with respect to the size of the collection.

Apart from that, I fail to see how you want to have a fixed-size ListBuffer on which you change the size with such trim methods…