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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>Think of metatypes as standalone types, which they actually are.</p>
<p>To get a metatype in Swift 2.2 we use this <code>TypeName.self</code> which return an instance of <code>TypeName.Type</code>.</p>
<p>Crystal clear right?</p>
<ul>
<li><code>Int.self</code> -> <code>Int.Type</code></li>
<li><code>UIView.self</code> -> <code>UIView.Type</code></li>
</ul>
<p>But there is one type which is bugged: <code>Any</code></p>
<ul>
<li><code>Any.self</code> -(is really)-> <code>Any.Type</code></li>
<li><code>Any.Type</code> in declarations is not equal the return type from <code>Any.self</code></li>
</ul>
<pre><code class="swift">// Swift 2.2
func test<T>(_ metatype: T.Type) { print(metatype) }
class A {}
let a = A()
let hidden: Any = A()
let dynamicAMetatype = a.dynamicType
// produces `Any.Type` which we expect
let dynamicAnyMetatype = hidden.dynamicType
test(dynamicAMetatype) // prints "A"
// BUT!!!!!
// ERROR: Cannot invoke 'test' with an argument list of type '(Any.Type)'
test(dynamicAnyMetatype)
</code></pre>
<p>This is a problem when you try to downcast your metatype to the metatype for <code>Any</code>.</p>
<p>A workaround is to use <code>Any.Type</code> which means is can only store any metatype (like: <code>Base.self</code>, <code>Derived.self</code>, <code>Any.self</code> etc.)</p>
<p>This is clearly a bug to me. <a href="https://bugs.swift.org/browse/SR-2085">SR–2085</a></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_1468598164972344832" 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 15. Juli 2016 um 17:12:29, Anton Zhilin (<a href="mailto:antonyzhilin@gmail.com">antonyzhilin@gmail.com</a>) schrieb:</p> <blockquote type="cite" class="clean_bq"><span><div><blockquote class="clean_bq" style="font-family: 'helvetica Neue', helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;"><div style="word-wrap: break-word;"><div><pre><span style="font-family: arial, sans-serif;">I just realized what causes the SR–2085 bug I mentioned earlier.</span><br></pre><ul><li><code>Any.Type</code><span class="Apple-converted-space"> </span>is not the metatype of<span class="Apple-converted-space"> </span><code>Any</code></li><li><code>Any.Type</code><span class="Apple-converted-space"> </span>means that this ‘thing’ can store any metatype</li><li>There is no type that expresses metatype for<span class="Apple-converted-space"> </span><code>Any</code></li><li>We still can get the metatype for<span class="Apple-converted-space"> </span><code>Any</code><span class="Apple-converted-space"> </span>through<span class="Apple-converted-space"> </span><code>Any.self</code></li></ul><p>I updated SR–2085 and suggested that we need<span class="Apple-converted-space"> </span><code>AnyMetatype</code>.</p></div></div></blockquote><div style="color: rgb(0, 0, 0); font-family: 'helvetica Neue', helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;">Why? I would prefer to be consistent and make<span class="Apple-converted-space"> </span><font face="monospace, monospace">Metatype<Any></font><span class="Apple-converted-space"> </span>the metatype of<span class="Apple-converted-space"> </span><font face="monospace, monospace">Any</font><span class="Apple-converted-space"> </span>(excuse the pun). And<span class="Apple-converted-space"> </span><i>because</i><span class="Apple-converted-space"> </span>all types are subtypes of<span class="Apple-converted-space"> </span><font face="monospace, monospace">Any</font>, instances of<span class="Apple-converted-space"> </span><font face="monospace, monospace">Metatype<Any></font><span class="Apple-converted-space"> </span>will still cover all types.</div></div></span></blockquote></div><div class="bloop_markdown"><p></p></div></body></html>