<div dir="ltr">Thanks for your response, Dave.<div><br></div><div>There is a bit of a dilemma here: wait until the generics and type system features have stabilized at the risk of making major source-breaking changes after 3.0, or make changes now without clarity about the future of the generics system.</div><div><br></div><div>Given that this topic showed up both in Chris's list of open design topics and in the generics manifesto, I assume that someone on the core team wanted a discussion about it before Swift 3 closes. I would be interested in knowing if that's true.</div><div><br></div><div>Best,</div><div>Austin</div><div><br></div><div><br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Jun 27, 2016 at 12:56 PM, Dave Abrahams via swift-evolution <span dir="ltr"><<a href="mailto:swift-evolution@swift.org" target="_blank">swift-evolution@swift.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class=""><br>
on Sat Jun 25 2016, Austin Zheng <<a href="mailto:swift-evolution@swift.org">swift-evolution@swift.org</a>> wrote:<br>
<br>
>> On Jun 25, 2016, at 6:23 AM, Matthew Johnson <<a href="mailto:matthew@anandabits.com">matthew@anandabits.com</a>> wrote:<br>
>><br>
>> Hi Austin,<br>
>><br>
>> I’m sorry to say, but this proposal makes me really sad. I consider<br>
>> associated type inference one of the more elegant aspects of Swift.<br>
>> It would be very unfortunate to lose it.<br>
><br>
> There are lots of "elegant" things that Swift could do, but has chosen<br>
> not to do for pragmatic reasons (e.g. generalized implicit<br>
> conversions, type inference that crosses statement boundaries). Given<br>
> how terrible the development experience can be right now in the worst<br>
> case, I would happily trade off some measure of convenience for better<br>
> tooling.<br>
<br>
</span>Well, the type checker's inference engine has *always* been kinda<br>
unreliable, and the experience is made much worse by the lack of<br>
recursive protocol requirements and the inability to express other<br>
constraints that would better guide inference, and by the “underscored<br>
protocols” such as _Indexable that are required to work around those<br>
limitations. IMO it's premature to remove this feature before the<br>
inference engine is made sane, the generics features are added, and the<br>
library is correspondingly cleaned up, because we don't really know what<br>
the user experience would be.<br>
<br>
Finally, I am very concerned that there are protocols such as Collection,<br>
with many inferrable associated types, and that conforming to these<br>
protocols could become *much* uglier.<br>
<span class="HOEnZb"><font color="#888888"><br>
--<br>
Dave<br>
</font></span><div class="HOEnZb"><div class="h5"><br>
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