On Thu, 27 May 2010 00:20:24 -0400, Jonathan M Davis
<[email protected]> wrote:
Steven Schveighoffer wrote:
Jonathan M Davis Wrote:
Looks interesting overall. There is one function, however, which makes
no
sense to me: removeElement()/stableRemoveElement().
So, it basically removes a random element from the container? It could
be
quite consistent as to which element it removes from the container (it
being implementation-dependent), but effectively, it removes a random
element? What's the point of that? I can't remember the last time - if
ever - that I wanted to remove an element from a container and I didn't
care which. Or am I misunderstanding what it does?
I think you are misunderstanding. Random element means you can't tell
which one is removed, but it doesn't *have* to be truly random :) It
most
likely will be the most convenient element to remove (maybe that would
be
a better description). In other words, you can't expect it to always be
the last element, or the first element, or the lowest element, or
whatever.
So essentially, I think that's what you were asking for, and I think
that's what Andrei meant.
-Steve
I don't think that I misunderstood, but I may not have stated it well.
No,
the element is not _truly_ random, but it is removing an unspecified
element
which could be any element in the container, and is therefore random in
the
sense that you aren't telling it which one to remove. I've never been in
a
situation where it made any sense to do that. So, the function struck me
as
really weird.
If you wanted truly random, you'd have to implement a function that
actually
did random number generation or whatnot to decide which element to pick,
and
presumably, it would be abnormal to use that here (though I think that
doing
so would still follow the API). So, no, removeElement() (now
removeAny()) is
not truly random, but it isn't deterministic from the perspective of the
programmer having any clue which one will be removed, and it may or may
not
be deterministic from the container's perspective.
OK. I think the point of removeAny is that it removes an element as fast
as possible, however that can be implemented by the container. I.e.
removing the back or front element may not be the fastest operation, think
about something like a tree, where the fastest element to remove is
probably the top element.
-Steve
