> On Dec 21, 2017, at 11:10 PM, Quincey Morris > <quinceymor...@rivergatesoftware.com> wrote: > > On Dec 21, 2017, at 18:04 , Daryle Walker <dary...@mac.com > <mailto:dary...@mac.com>> wrote: >> >> when multiple blocks are used > > At this point, I don’t understand what you don’t understand. Here’s a code > fragment that works in a playground: > >> import Foundation >> >> let buffer1: [UInt8] = [1,2] >> let buffer2: [UInt8] = [3,4,5,6] >> >> var data = DispatchData.empty >> data.append (buffer1.withUnsafeBytes { DispatchData (bytesNoCopy: $0) }) >> data.append (buffer2.withUnsafeBytes { DispatchData (bytesNoCopy: $0) }) >> >> print (data.count) >> data.enumerateBytes { >> bytes, index, stop in >> print (bytes.count, index, bytes [0]) >> } > > producing this output: > >> 6 >> 2 0 1 >> 4 2 3 > > Isn’t this what you were asking for: a loop enumerating each of the > contiguous portions of a larger data set?
I already have the code as an extension of Data. In C, we can use pointer type-punning shenanigans to convert between a dispatch_data_t and NSData*. To trigger this code in a test that I would write in Swift, DispatchData would need to be convertible to Data. Is there a way to do the conversion in Swift? It doesn’t seem obvious since DispatchData and Data are value types, not pointer nor reference types. I just checked it out with your code above in a playground. I added an extension to Data called “printHello” and called it with a Data object I also added. Sure enough, the DispatchData object could not call that same method. — Daryle Walker Mac, Internet, and Video Game Junkie darylew AT mac DOT com _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
