swift3 - Swift 3 UnsafePointer($0) 不再在 Xcode 8 beta 6 中编译

Question

我的代码片段如下......:

    let defaultRouteReachability = withUnsafePointer(to: &zeroAddress) {
        SCNetworkReachabilityCreateWithAddress(nil, UnsafePointer($0))
    }

...不再编译并出现以下我不明白的错误:

"'init' is unavailable: use 'withMemoryRebound(to:capacity:_)' to temporarily view memory as another layout-compatible type."

如何解决这个问题？

Answer 1

来自 Xcode 8 beta 6 的发行说明:

• An Unsafe[Mutable]RawPointer type has been introduced, replacing Unsafe[Mutable]Pointer<Void>. Conversion from UnsafePointer<T> to UnsafePointer<U> has been disallowed. Unsafe[Mutable]RawPointer provides an API for untyped memory access, and an API for binding memory to a type. Binding memory allows for safe conversion between pointer types. See bindMemory(to:capacity:), assumingMemoryBound(to:), and withMemoryRebound(to:capacity:). (SE-0107)

根据您的情况，您可能需要编写如下内容:

let defaultRouteReachability = withUnsafePointer(to: &zeroAddress) {
    $0.withMemoryRebound(to: sockaddr.self, capacity: 1) {zeroSockAddress in
        SCNetworkReachabilityCreateWithAddress(nil, zeroSockAddress)
    }
}