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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>For more information about optional chaining read this docs: <a href="https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/OptionalChaining.html">https://developer.apple.com/library/content/documentation/Swift/Conceptual/Swift_Programming_Language/OptionalChaining.html</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_1486581136353139968" 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 8. Februar 2017 um 20:05:31, Adrian Zubarev (<a href="mailto:adrian.zubarev@devandartist.com">adrian.zubarev@devandartist.com</a>) schrieb:</p> <blockquote type="cite" class="clean_bq"><span><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div></div><div>
<title></title>
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<p>Swift does already have a great solution in such a scenario.</p>
<pre><code class="swift">func handler() -> Result? {
return callback?.result()
}
</code></pre>
<p>Does the trick. ;)</p>
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<div id="bloop_sign_1486580647439058176" class="bloop_sign">
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-- <br>
Adrian Zubarev<br>
Sent with Airmail</div>
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<p class="airmail_on">Am 8. Februar 2017 um 20:02:38, Maxim Veksler
(<a href="mailto:maxim@vekslers.org">maxim@vekslers.org</a>)
schrieb:</p>
<blockquote type="cite" class="clean_bq">
<div>
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<span>For example, assume that we're dealing with a callback of
some form.</span></div>
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<span><br></span></div>
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<span><font face="monospace">let callback: CallbackProtocol? =
StructExampleCallback()</font></span></div>
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<span><br></span></div>
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<span>You could write inside you handler function:</span></div>
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<span><br></span></div>
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<span><font face="monospace">func handler() -> Result?
{</font></span></div>
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<span><font face="monospace"> return callback ?!
callback.result() : nil</font></span></div>
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<span><font face="monospace">}</font></span></div>
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<span><br></span></div>
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<span>Which would return either nil, or the callback result. I
don't think you can do it with ?? but then again guard is a valid
solution for this specific use case.</span></div>
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