On 3/14/2014 3:06 AM, Don wrote:
Our entire codebase assumes that stomping will happen. Simplest example:
T[] dupArray(T)(ref T[] dest, T[] src)
{
dest.length = src.length;
if (src.length) {
dest[] = src[];
}
return dest;
}
This is equivalent to dest = src.dup, but if dest was already long enough to
contain src, no allocation occurs.
Sure, we can add a call to "assumeSafeAppend()" everywhere. And I mean
*everywhere*. Every single instance of array creation or concatentation, without
exception. Almost every array in our codebase is affected by this.
I see. I'd start by replacing T[] with:
alias T[] Q;
and then using Q instead of T[]. Once that is done, you can experiment with
different implementations of Q. In my own D code, I've found this to be very
effective. It's great to be able to swap in/out utterly different
implementations of Q and measure performance.
