Swift 4.1 取消初始化和解除分配(容量 :) deprecated

Question

我一直在这样说来形成 CGPoint 的 C 数组:

let arr = UnsafeMutablePointer<CGPoint>.allocate(capacity:4)
defer {
    arr.deinitialize()
    arr.deallocate(capacity:4)
}
arr[0] = CGPoint(x:0,y:0)
arr[1] = CGPoint(x:50,y:50)
arr[2] = CGPoint(x:50,y:50)
arr[3] = CGPoint(x:0,y:100)

现在(Xcode 9.3 beta 中的 Swift 4.1)deinitialize 和 deallocate(capacity:) 都被弃用了。看来我现在应该说的可能是:

defer {
    arr.deinitialize(count:4)
    arr.deallocate()
}

是这样吗？

Answer 1

是的，那是 SE-0184 Unsafe[Mutable][Raw][Buffer]Pointer: add missing methods, adjust existing labels for clarity, and remove deallocation size 的一部分,已在 Swift 4.1 中实现。

特别是:

Removing capacity from deallocate(capacity:) will end the confusion over what deallocate() does, making it obvious that deallocate() will free the entire memory block at self, just as if free() were called on it.

The old deallocate(capacity:) method should be marked as deprecated and eventually removed since it currently encourages dangerously incorrect code.