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.send { color:#77bb77; }
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.error { color:#AA0000; }</style></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div class="bloop_markdown"><p>Well I simply reused the existing keywords as part of the closure type to demonstrate the idea here as easy as possible.</p>
<p>About the _true_ weak/unowned closures. First I asked John McCall on twitter about this whole idea. Here is his reply about the _true_ weak closures:</p>
<blockquote>
<p>You mean a weak reference to a closure? No, I don’t think we’d ever want to assign closure values enough identity to give that meaning.</p>
</blockquote>
<p>I get it, that it might be not quite obvious or even confusing why <code>weak/unowned</code> can be applied on a type and on a variable. However <code>weak</code> is always an <code>Optional</code> or an <code>IUO</code> where <code>unowned</code> is non-optional. </p>
<p>Just my personal thoughts: Could we potentially align <code>weak/unowned</code> with <code>inout</code> and make it type decoration? (This would be a breaking change.)</p>
<p></p></div><div class="bloop_original_html"><style>body{font-family:Helvetica,Arial;font-size:13px}</style><div id="bloop_customfont" style="font-family:Helvetica,Arial;font-size:13px; color: rgba(0,0,0,1.0); margin: 0px; line-height: auto;"><br></div> <br> <div id="bloop_sign_1497124159511079168" class="bloop_sign"><div style="font-family:helvetica,arial;font-size:13px">-- <br>Adrian Zubarev<br>Sent with Airmail</div></div> <br><p class="airmail_on">Am 10. Juni 2017 um 21:44:41, Gor Gyolchanyan (<a href="mailto:gor@gyolchanyan.com">gor@gyolchanyan.com</a>) schrieb:</p> <blockquote type="cite" class="clean_bq"><span><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div></div><div>
<title></title>
I don't think it's a good idea to make the `weak`-ness of the
closure part of the type system.
<div class="">The current approach to `weak/unowned` is that it's a
storage class that applies to the variable, not the value.</div>
<div class="">This makes sense because you don't *use* a weak
reference, you only *store* it weakly.</div>
<div class="">I think this behavior has to stay the same with the
addition of closures (being the other reference type along classes)
would be eligible for storing by `weak/unowned`
reference.<br class="">
<div><br class="">
<blockquote type="cite" class="">
<div class="">On Jun 10, 2017, at 10:39 PM, Adrian Zubarev via
swift-evolution <<a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a>> wrote:</div>
<br class="Apple-interchange-newline">
<div class="">
<div class="bloop_markdown" style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254);">
<p style="margin: 15px 0px; -webkit-margin-before: 0px;" class="">
Hi Matthew,</p>
<p style="margin: 15px 0px;" class="">Thank you for the hint.
Indeed, at first glance your proposal is very similar to my
thinking. I’ll try to dive deeper into your proposal and find out
more about the discussion behind it when I get some more time for
that.</p>
<p style="margin: 15px 0px;" class="">We could collaborate on a
revision for Swift 5 if you would like to, but we wouldn’t need to
rush now, because there is plenty of time for that.<span class="Apple-converted-space"> </span></p>
<p style="margin: 15px 0px;" class="">Personally I would love to
avoid some kind of a prefix like<span class="Apple-converted-space"> </span><code style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;" class="">?</code><span class="Apple-converted-space"> </span>if possible.</p>
<p style="margin: 15px 0px;" class="">Brainstorming:</p>
<p style="margin: 15px 0px;" class=""><code style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;" class="">let c1 = weak someObject.method</code><span class="Apple-converted-space"> </span>convert it to a weak
closure.</p>
<p style="margin: 15px 0px;" class=""><code style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;" class="">let c2: weak (CLOSURETYPE)? =
someObject.method</code><span class="Apple-converted-space"> </span>Let the compiler do the job
for us.</p>
<p style="margin: 15px 0px;" class="">The latter would be great for
APIs to avoid the prefix.</p>
<p style="margin: 15px 0px;" class=""><code style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;" class="">.subscribe(onNext: self.bar)</code><span class="Apple-converted-space"> </span><code style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal;" class="">weak</code><span class="Apple-converted-space"> </span>is inferred and can be
omitted<span class="Apple-converted-space"> </span></p>
<div style="margin: 15px 0px;" class=""><br class="webkit-block-placeholder"></div>
</div>
<div class="bloop_original_html" style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254);">
<div id="bloop_customfont" style="font-family: Helvetica, Arial; font-size: 13px; margin: 0px;" class=""><br class=""></div>
<br class="">
<div id="bloop_sign_1497122959888763904" class="bloop_sign">
<div style="font-family: helvetica, arial; font-size: 13px;" class="">-- <br class="">
Adrian Zubarev<br class="">
Sent with Airmail</div>
</div>
<br class="">
<p class="airmail_on" style="margin: 15px 0px;">Am 10. Juni 2017 um
21:09:28, Matthew Johnson (<a href="mailto:matthew@anandabits.com" style="color: rgb(65, 131, 196); background-color: inherit; text-decoration: none;" class="">matthew@anandabits.com</a>) schrieb:</p>
<blockquote type="cite" class="clean_bq" style="margin: 15px 0px;">
<div class="" style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;">
<div class=""></div>
<div class=""><span style="margin-top: 0px; margin-bottom: 0px;" class="">Hi Adrian, this is pretty similar to the Guarded Closures
proposal I drafted in February. This proposal needs a
revision incorporating discussion feedback and some new ideas.
If you’re interested, here’s a link to the original
discussion thread: <a href="https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20170213/032478.html" class="" style="color: rgb(65, 131, 196); background-color: inherit; text-decoration: none;">https://lists.swift.org/pipermail/swift-evolution/Week-of-Mon-20170213/032478.html</a>.</span>
<div class=""><span style="margin-top: 0px; margin-bottom: 0px;" class=""><br class=""></span>
<div class="">
<blockquote type="cite" class="" style="margin: 15px 0px;">
<div class="" style="margin-top: 0px;"><span style="margin-top: 0px; margin-bottom: 0px;" class="">On Jun 10, 2017, at
12:29 PM, Adrian Zubarev via swift-evolution <<a href="mailto:swift-evolution@swift.org" class="" style="color: rgb(65, 131, 196); background-color: inherit; text-decoration: none;">swift-evolution@swift.org</a>>
wrote:</span></div>
<span style="margin-top: 0px; margin-bottom: 0px;" class=""><br class="Apple-interchange-newline"></span>
<div class="" style="margin-bottom: 0px;">
<div class="bloop_markdown" style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254);">
<p class="" style="margin: 15px 0px; -webkit-margin-before: 0px;">
<span style="margin-top: 0px; margin-bottom: 0px;" class="">Hello
Evolution,</span></p>
<p class="" style="margin: 15px 0px;"><span style="margin-top: 0px; margin-bottom: 0px;" class="">I’d like to pitch a
new idea and see where it would go. Recently I tapped into a small
trap and just now realized that even that<span class="Apple-converted-space" style="-webkit-margin-before: 0px;"> </span><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;">non-escaping</code><span class="Apple-converted-space"> </span>should
have been the default for closures (SE–0103) there is an exception
for that. Apparently generics don’t follow that rule and a closure
like<span class="Apple-converted-space"> </span></span></p>
<p class="" style="margin: 15px 0px;"><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;">
Optional<() -> Void></code><span class="Apple-converted-space"> </span>or simply<span class="Apple-converted-space"> </span><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal;">(()
-> Void)?</code></p>
<p class="" style="margin: 15px 0px;">is still escaping by default.
But that was the half of the story yet. As we all know and “love”
reference lists inside closures, methods don’t have any and we have
to wrap method calls into a weak referenced closure<span class="Apple-converted-space" style="-webkit-margin-before: 0px;"> </span></p>
<p class="" style="margin: 15px 0px;"><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;">
{ [weak self] in self.foo() }</code></p>
<p class="" style="margin: 15px 0px;">to avoid strong reference
cycles. Maybe you already guess it, I accidentally didn’t and
tapped into the land of strong reference cycles yet again on my
journey.</p>
<p class="" style="margin: 15px 0px;">I’d like to pitch a new way,
more like a new type behavior, for closures on how they could be
used differently in order to avoid strong reference cycles but also
providing the ability to use methods without any need to wrap
them.</p>
<p class="" style="margin: 15px 0px;">Here is a simple code snippet
using RxSwift, which will recreate my issue:</p>
<pre class="" style="margin: 15px 0px; font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(204, 204, 204); overflow: auto; padding: 4px 8px; word-break: normal; word-wrap: normal;"><code class="swift" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 0px; margin: 0px; padding: 0px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;">import RxSwift
let test = PublishSubject<Void>()
class A {
let disposeBag = DisposeBag()
func foo() {
test.asObservable()
.subscribe(onNext: self.bar) // The issue is here
.disposed(by: self.disposeBag)
}
func bar() { print("works") }
}
let a = A()
a.foo()
test.onNext(()) // Testing if it works
test.onCompleted() // Some RxSwift stuff
</code></pre>
<p class="" style="margin: 15px 0px;">In this case by passing
directly the method<span class="Apple-converted-space" style="-webkit-margin-before: 0px;"> </span><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;">self.bar</code><span class="Apple-converted-space"> </span>we’re
capturing<span class="Apple-converted-space"> </span><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal;">self</code>,
which in this situation isn’t our intention at all. To avoid this
issue we can simply wrap the method call into closure:</p>
<p class="" style="margin: 15px 0px;"><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;">
.subscribe(onNext: { [unowned self] in self.bar() })</code></p>
<p class="" style="margin: 15px 0px;">(It’s safe to make it unowned
because the dispose bag is a member of<span class="Apple-converted-space" style="-webkit-margin-before: 0px;"> </span><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;">self</code>.)</p>
<hr class="" style="height: 0.2em; border: 0px; color: rgb(204, 204, 204); background-color: rgb(204, 204, 204); display: inherit;">
<p class="" style="margin: 15px 0px;">What if we had the ability
for weak or unowned closures? By that I don’t mean weak/unowned
references to the closures themselves, because they are also
reference types, but an invalidation behavior for the whole closure
based on the _captured_ references. For instance:</p>
<p class="" style="margin: 15px 0px;"><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;">
let closure1: weak (() -> Void)? = { self.doWhatever()
}</code></p>
<p class="" style="margin: 15px 0px;"><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;">
let closure2: weak (() -> Void)? = self.doWhatever</code></p>
<p class="" style="margin: 15px 0px;">If one would now try to call
the<span class="Apple-converted-space" style="-webkit-margin-before: 0px;"> </span><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;">closure</code>,
first it will check if all the captured objects are still available
or not, if not the whole closure in this case will simply
become<span class="Apple-converted-space"> </span><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal;">nil</code><span class="Apple-converted-space"> </span>and
won’t execute. In case of unowned closures it will trap.
Furthermore it will support the general meaning of<span class="Apple-converted-space"> </span><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal;">weak/unowned</code><span class="Apple-converted-space"> </span>and
will not increase the reference counter for *captured objects*.</p>
<p class="" style="margin: 15px 0px;">As you have already noticed,
in this case the convention is slightly different because we must
carry the behavior directly with the type.</p>
<p class="" style="margin: 15px 0px;"><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;">
func subscribe(onNext: weak ((Swift.E) -> Void)?)</code></p>
<p class="" style="margin: 15px 0px;">If the way of my thinking is
correct this idea _could maybe_ fade out the very
common<span class="Apple-converted-space" style="-webkit-margin-before: 0px;"> </span><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;">[weak
self] in guard let strongSelf = self …</code><span class="Apple-converted-space"> </span>pattern.<span class="Apple-converted-space"> </span></p>
<hr class="" style="height: 0.2em; border: 0px; color: rgb(204, 204, 204); background-color: rgb(204, 204, 204); display: inherit;">
<p class="" style="margin: 15px 0px;">I personally cannot tell all
the technical difficulties this idea might have, but that’s what
the evolution list is for, to collaboratively flesh out the ideas
if they are worth it.</p>
<hr class="" style="height: 0.2em; border: 0px; color: rgb(204, 204, 204); background-color: rgb(204, 204, 204); display: inherit;">
<p class="" style="margin: 15px 0px;">If something like this could
be possible it’s probably worth noting that we might also be able
to introduce something like<span class="Apple-converted-space" style="-webkit-margin-before: 0px;"> </span><code class="" style="font-family: Menlo, Consolas, 'Liberation Mono', Courier, monospace; font-size: 10pt; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; background-color: rgb(248, 248, 248); color: inherit; border: 1px solid rgb(234, 234, 234); margin: 0px 2px; padding: 0px 5px; word-break: normal; word-wrap: normal; -webkit-margin-before: 0px;">@autoclosure(weak/unowned)</code><span class="Apple-converted-space"> </span>to
Swift for consistency.</p>
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-- <br class="">
Adrian Zubarev<br class="">
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<div class="bloop_markdown" style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254);">
<div class="" style="-webkit-margin-before: 0px; margin: 15px 0px;"><br class="webkit-block-placeholder" style="-webkit-margin-before: 0px;"></div>
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<span class="" style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254); float: none; display: inline !important;">_______________________________________________</span><br class="" style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254);">
<span class="" style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254); float: none; display: inline !important;">
swift-evolution mailing list</span><br class="" style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254);">
<a href="mailto:swift-evolution@swift.org" class="" style="color: rgb(65, 131, 196); background-color: rgb(254, 254, 254); text-decoration: none; font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;">
swift-evolution@swift.org</a><br class="" style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254);">
<a href="https://lists.swift.org/mailman/listinfo/swift-evolution" class="" style="color: rgb(65, 131, 196); background-color: rgb(254, 254, 254); text-decoration: none; font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px;">
https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class="" style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254);">
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<div class="bloop_markdown" style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254);">
<div style="margin: 15px 0px; -webkit-margin-before: 0px;" class=""><br class="webkit-block-placeholder"></div>
</div>
<span style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254); float: none; display: inline !important;" class="">_______________________________________________</span><br style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254);" class="">
<span style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254); float: none; display: inline !important;" class="">swift-evolution mailing list</span><br style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254);" class="">
<span style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254); float: none; display: inline !important;" class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a></span><br style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254);" class="">
<span style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254); float: none; display: inline !important;" class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a></span><br style="font-family: Helvetica, Arial; font-size: 13px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(254, 254, 254);" class=""></div>
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