<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=""><div class="">I’ve been trying to get the maximum of a list of counts. I started by using “myCollection.map { $0.myCountProperty }.reduce(0, max)”. Then I thought I should really use the value closest to negative infinity as the base. The problem is how to get that value. The current hard-coded “0” works because the count type ultimately aliases “Int”, but shouldn’t have to count on that. I put in “MyCountType.min”, where “MyCountType” is hard coded from the docs of “myCountProperty”, but I shouldn’t have to do that either.</div><div class=""><br class=""></div><div class="">There is a “type(of:)” global function, which I did use. But not only did I have to make up an expression to go in there, its return value, some sort of meta-type stuff I don’t understand, can’t be used on the right side of a “typealias” construct. I ultimately used “let lowestCount = type(of: anElement.myCountProperty).min” to get what I needed.</div><div class=""><br class=""></div><div class="">Some queries/requests:</div><div class=""><br class=""></div><div class="">1. Is the expression within “type(of:)” evaluated?</div><div class="">2. I think we need the equivalent of "std::declval” from C++. Especially if the answer to (1) is yes.</div><div class="">3. Why isn’t the return type(?) of “type(of:)” compile-time enough to be used as a type-alias?</div><div class="">4. Should we add something like the C++ type-traits collection of generic structures to give use type information as type-aliases or type-level instances?</div><div class=""><br class=""></div><div class="">
<div style="color: rgb(0, 0, 0); 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; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">— </div><div class="">Daryle Walker<br class="">Mac, Internet, and Video Game Junkie<br class="">darylew AT mac DOT com </div></div>
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