container/list: MoveBefore/After would be useful

[rogpeppe]

Currently there's no way of moving a list element to
an arbitrary place in the list without removing it
and using InsertBefore/After.

It's useful to be able to have external data structures
pointing at list elements that can move around arbitrarily,
so I suggest two new List methods:

// MoveAfter moves the element immediately after mark.
func (l *List) MoveAfter(e, mark *Element)

// MoveBefore moves the element immediately before mark.
func (l *List) MoveBefore(e, mark *Element)

[rsc]

Comment 1:

[The time for maybe has passed.]

Labels changed: removed go1.1maybe.

[rsc]

Comment 2:

Labels changed: added go1.2maybe, feature.

Status changed to Accepted.

[PieterD]

Comment 3:

I submitted a CL for this:
https://golang.org/cl/12021044/

[griesemer]

Comment 4:

This issue was closed by revision fbcc24b.

Status changed to Fixed.