> On May 20, 2016, at 7:33 AM, Ken Burgett via swift-users > <swift-users@swift.org> wrote: > > I have been told that the in-memory layout of a Swift struct is 'undefined', > so the C style of aliasing an array over a struct and iterating across the > struct is a definite no-no. Not surprising, since aliasing violates all > type-safe rules. > > So, if you have this situation, you must address it on a case-by-case basis. > In my case, converting a hash algorithm from C to Swift, the required C > struct morphs into a Swift class, with a member function 'as_C_byte_array' > which answers an array of the required form. Internally, this function will > shift and mask class attributes in order to build the necessary result.
That's not necessary. You can leave the struct defined in C and import it into Swift. Swift will respect C's layout. -Joe > Ugly, but I must preserve the semantics exactly if I hope to generate the > exact same hash as the C version. > > -- > Ken Burgett > Principal Software Engineer > Email: k...@iotone.io > Office: 530.693.4449 > Mobile: 831.332.6846 > URL: www.iotone.co > _______________________________________________ > swift-users mailing list > swift-users@swift.org > https://lists.swift.org/mailman/listinfo/swift-users _______________________________________________ swift-users mailing list swift-users@swift.org https://lists.swift.org/mailman/listinfo/swift-users
