<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">On Aug 18, 2017, at 7:38 AM, Matthew Johnson 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=""><span style="font-family: Helvetica; font-size: 12px; 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; float: none; display: inline !important;" class="">I would like to reiterate the point I made in the question that spawned this thread: there are *many* Swift libraries for writing async code of various sorts which are *already* using typed errors via `Result<Value, ErrorType: Error>`. We don't have to speculate about how this feature might be used and what kind of benefits might be realized. We can have a discussion about what people are already doing and determine whether this model should be supported in the async / await world or not. What do you think of putting a call out to the broader Swift community to bring us concrete examples of how they are benefiting from using typed errors in async code.</span><br style="font-family: Helvetica; font-size: 12px; 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;" class=""></div></blockquote><br class=""></div><div>I have found this “feature" has been painful to use. I have been forced to wrap hetrogenous errors in a custom error type just to satisfy these ill-conceived APIs. i have never found any benefit to ```ErrorType: Error``` generic parameter. … Any. Ever.</div><br class=""></body></html>