<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 agree, given the current state of Swift, fixed-sized arrays are way too magical.</div><div class="">I’d suggest postponing the idea of fixed-sized arrays (even though I myself have ached for them for a long time now) until its prerequisites are met.</div><div class=""><br class=""></div><div class="">There are three language features that have been discusses before that are required for this:</div><div class=""><ul class="MailOutline"><li class="">Variadic generic parameters.</li><li class="">Tuples as nominal types with a variadic generic parameter and a tuple concatenation ability.</li><li class="">Non-type generic parameters (probably, only compile-time value types).</li></ul></div><div class=""><br class=""></div><div class="">In these terms, a fixed-sized array would be a type that takes an <font face="PT Mono" color="#009051" class="">Int</font> as a generic parameter and uses a variadic tuple for its storage. If C++ templates has taught us anything is that metaprogramming can be used for achieving fantastic compile-time wizardry, like converting a single integer generic parameter and a single generic type parameter to a generic homogeneous variadic type parameter (by using a recursively defined variadic parameter dummy type).</div><br class=""><div><blockquote type="cite" class=""><div class="">On Jul 12, 2017, at 11:11 PM, Robert Widmann 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=""><meta http-equiv="Content-Type" content="text/html; charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">I think this proposal is trying to do too much at once. Correct me if I’m wrong, but you’re proposing<div class=""><br class=""></div><div class="">1) New sugar for fixed-length arrays without a corresponding stdlib declaration</div><div class="">2) Arity and type inference for literals</div><div class="">3) Default initialization semantics for arrays including a DI exception for fixed-length arrays that aren’t fully initialized </div><div class="">4) 2 new attribute declarations for unspecified concurrency semantics</div><div class="">5) A magical compiler intrinsic that declares loop counters</div><div class="">6) Static collection subtyping constraints referencing convertibility constraints we don’t currently have<br class=""><div class=""><div class="">7) Tuple conversions</div><div class=""><br class=""></div><div class="">I believe your aims are noble, and this is certainly a tremendously important problem we need to solve, but I think there needs to be a measured response to the current state of things.</div><div class=""><br class=""></div><div class="">~Robert Widmann</div><div class=""><br class=""><blockquote type="cite" class=""><div class="">On Jul 10, 2017, at 9:54 PM, Daryle Walker 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=""><meta http-equiv="content-type" content="text/html; charset=utf-8" class=""><div dir="auto" class=""><div class="">Spent the past week coming up with a full proposal for fixed-size arrays. I wrote it mainly from the bottom upwards. There may be some inconsistencies. And I'm not entirely sure what "<span style="background-color: rgba(255, 255, 255, 0);" class="">structural sub-typing" means, or if it's appropriate for arrays.</span></div><div class=""><br class=""></div><div class=""><<a href="https://gist.github.com/CTMacUser/cfffa526b971d0e1f3a079f53c6819bb#file-nnnn-fixed-size-arrays-md" class="">https://gist.github.com/CTMacUser/cfffa526b971d0e1f3a079f53c6819bb</a>><br class=""><br class=""><div class="">Sent from my iPad</div></div></div>_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a><br class=""><a href="https://lists.swift.org/mailman/listinfo/swift-evolution" class="">https://lists.swift.org/mailman/listinfo/swift-evolution</a><br class=""></div></blockquote></div><br class=""></div></div></div>_______________________________________________<br class="">swift-evolution mailing list<br class=""><a href="mailto:swift-evolution@swift.org" class="">swift-evolution@swift.org</a><br class="">https://lists.swift.org/mailman/listinfo/swift-evolution<br class=""></div></blockquote></div><br class=""></body></html>