Am 03.11.2016 um 15:41 schrieb Rien <r...@balancingrock.nl>: > > Ah, but that is not the case. > > It is important to differentiate between the “gateway” to the memory and the > memory area itself. > Different programming languages/compilers have different approaches, but I > believe that Swift allocates a struct for every gateway. > widePtr and narrowPtr are two different gateways. They refer to different > struct's. But the struct for each of them refers to the same memory area.
When you have a look at the Swift memory model explanation https://github.com/apple/swift-evolution/blob/master/proposals/0107-unsaferawpointer.md#memory-model-explanation it looks like memory can only be bound to one type at a time. In particular in the third example where a pointer of type T is used to initialize memory which is bound to type U, it says that the behavior is undefined. There is also withMemoryRebound(to:capacity:) which binds memory to another type, executes the code that accesses the memory as this type in a closure, and the restores the old type binding. That makes me think that it is not allowed to have multiple „gateways“ to the same memory area at the same time. Manfred _______________________________________________ swift-users mailing list swift-users@swift.org https://lists.swift.org/mailman/listinfo/swift-users
