<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><br><div><div>On Mar 14, 2012, at 11:34 AM, Matt Joiner wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><span class="Apple-style-span" style="border-collapse: separate; font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; font-size: medium; ">There's still a performance cost in looking up the already present value a second time.</span></blockquote></div><br><div>The performance cost is near zero. The relevant memory accesses with be in cache (which make accessing them almost free).</div><div><br></div><div>Besides, the price you pay for storing and testing the boolean value isn't free either. </div><div><br></div><div>Thinking like a C programmer won't help you in the optimization game with sets.</div><div>And, it's certainly not worth complexifying the API.</div><div><br></div><div><br></div><div>Raymond</div><div><br></div><div><br></div><div>P.S. There have been previous threads on this same subject and they've all ended with rejecting the proposal.</div><div><br></div><div><br></div></body></html>