on Thu Jun 30 2016, Xiaodi Wu <xiaodi.wu-AT-gmail.com> wrote: > On Thu, Jun 30, 2016 at 2:30 PM, Dave Abrahams <[email protected]> wrote: > >> >> on Wed Jun 29 2016, Erica Sadun <erica-AT-ericasadun.com> wrote: >> >> >> On Jun 29, 2016, at 3:59 PM, Xiaodi Wu via swift-evolution < >> [email protected]> wrote: >> >> >> >> On Wed, Jun 29, 2016 at 4:50 PM, David Sweeris <[email protected] >> <mailto:[email protected]>> wrote: >> >> That’s the “as proposed” usage for getting the size of a value (from >> >> https://gist.github.com/erica/57a64163870486468180b8bab8a6294e >> > >> >> <https://gist.github.com/erica/57a64163870486468180b8bab8a6294e>) >> >> // Types >> >> MemoryLayout<Int>.size // 8 >> >> MemoryLayout<Int>.arraySpacing // 8 >> >> MemoryLayout<Int>.alignment // 8 >> >> >> >> // Value >> >> let x: UInt8 = 5 >> >> MemoryLayout(x).dynamicType.size // 1 >> >> MemoryLayout("hello").dynamicType.arraySpacing // 24 >> >> MemoryLayout(29.2).dynamicType.alignment // 8 >> >> >> >> >> >> At least, I thought that was the latest version of the proposal. Maybe >> I’ve gotten confused. >> >> >> >> There must be a typo in these examples. >> `MemoryLayout(x.dynamicType).size` perhaps? >> > >> > I have listened. I have updated. >> > >> > https://gist.github.com/erica/57a64163870486468180b8bab8a6294e >> > >> > // Types >> > MemoryLayout<Int>.size // 8 >> > MemoryLayout<Int>.arraySpacing // 8 >> > MemoryLayout<Int>.alignment // 8 >> > >> > // Value >> > let x: UInt8 = 5 >> > MemoryLayout.of(x).size // 1 >> > MemoryLayout.of(1).size // 8 >> > MemoryLayout.of("hello").arraySpacing // 24 >> > MemoryLayout.of(29.2).alignment // 8 >> >> I am still very skeptical that anyone needs the “Value” version, and as >> long as we're resyntaxing I am inclined to take it away and see how many >> people complain. You can still always write it yourself. >> > > So long as the issue regarding querying an existential value's dynamic type > is addressed, yes?
Oh, I guess that's right. > I mentioned this in a comment on the gist already, but I'm really not > digging the "array" in `arraySpacing`. We've already moved from top-level > "stride" to "memory layout spacing," gaining plenty of clarity. I'm > skeptical that the "array" adds anything more. Moreover, it muddies the > waters by mentioning a specific type (Array) in a context where you're > querying the memory layout properties of another type. OK, I agree with that. If we have “alignment” rather than “defaultAlignment,” I suppose we can have plain “spacing.” -- Dave _______________________________________________ swift-evolution mailing list [email protected] https://lists.swift.org/mailman/listinfo/swift-evolution
