On Mon, 16 May 2011 15:23:31 -0400, Mehrdad <wfunct...@hotmail.com> wrote:
Steven:
You need to do arr.assumeSafeAppend(); Otherwise, the runtime is no
aware of your invalidation of the last element.
See my edit on SO: http://stackoverflow.com/q/6015008/541686
I'm not an SO user, so I'll post my answer here:
assumeSafeAppend is named that way because you are making an assumption,
possibly an unsafe one :) You are saying, "hey, runtime, assume that
despite what you know about this array's data, it's safe to append in this
case," and the runtime says "ok, boss, no problem." It cannot tell that
you intended to use that data you have just invalidated.
What you want to do is determine if the array is safe to append *before*
you eliminate the elements at the end (i.e. the elements you are "throwing
away" are at the end of valid data anyways). You can do this with the
capacity property:
auto oldcap = arr.capacity;
// do your dirty work
...
if(oldcap) // capacity != 0 means you could originally append to this
array, or that it filled up the block.
arr.assumeSafeAppend();
This should do the trick.
-Steve
