Hi,
It seems that the built-in append does not check for a situation like
the following, and needlessly copies data, when it could avoid it.
func appendBytes(a, b []byte) []byte {
if len(b) == 0 {
return a
}
// Shouldn't append() check for something like this?
if cap(a) >= len(a)+len(b) && &a[:len(a)+1][len(a)] == &b[0] {
return a[:len(a)+len(b)]
}
return append(a, b...)
}
If I'm following the breadcrumbs correctly, they lead to the fact that
runtime-memmove() does *not* short-circuit when source and destination
addresses are the same (I may be wrong, though).
Running the benchmark at:
https://gist.github.com/npat-efault/f055654633f43d0ef771d38657fd499e
for any value of N, demonstrates this.
Rather marginal (and possibly very contrived) case, but I though I'd
point it out...
/npat
--
You received this message because you are subscribed to the Google Groups
"golang-nuts" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to golang-nuts+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
