> On 20 May 2017, at 19:58, Philippe Hausler wrote: > >> On May 20, 2017, at 12:25 AM, David Waite wrote: >> >> I believe behavior depends on whether the NSNumber is the objc type or swift >> subtype, and whether you call the NSNumber.intValue or use >> Int.init?(exactly: NSNumber). > > That part of the behavior is no longer the case. The bridge only transacts > upon one number type (to leverage tagged pointers) and the subclass was > removed (since it caused some gnarly inconsistencies)
The subclass `_SwiftTypePreservingNSNumber` still exists: <https://github.com/apple/swift/blob/master/stdlib/public/SDK/Foundation/TypePreservingNSNumber.mm> Maybe the file isn't compiled anymore due to your pull requests: <https://github.com/apple/swift/pull/9162> <https://github.com/apple/swift/pull/9293> You mentioned tagged pointers. My understanding is that: * `OBJC_TAG_NSNumber` doesn't attempt to store a `float` or `double` in the 60-bit payload; * `OBJC_TAG_NSDate` is used only if bits 0...3 of the `NSTimeInterval` (aka `double`) are zero. <https://opensource.apple.com/source/objc4/objc4-709/runtime/objc-internal.h.auto.html> How often is an NSDate (with "sub-millisecond precision") created as a tagged pointer? -- Ben _______________________________________________ swift-evolution mailing list swift-evolution@swift.org https://lists.swift.org/mailman/listinfo/swift-evolution
