stl list - complexity

Question

Are all the inserts (anywhere) for the list constant?

What about access?

Front, back - constant time?

and in the middle of the list - linear time?

Answer 1

http://www.sgi.com/tech/stl/List.html

A list is a doubly linked list. That is, it is a Sequence that supports both forward and backward traversal, and (amortized) constant time insertion and removal of elements at the beginning or the end, or in the middle. Lists have the important property that insertion and splicing do not invalidate iterators to list elements, and that even removal invalidates only the iterators that point to the elements that are removed

With regards to access, if you're going to search for an element somewhere in the middle, it'll take linear time. But once you've got an iterator, it'll be (of course) constant time access, and it won't be invalidated by other insertions or removals.