Ah the missing part of the puzzle appears to be unsafeBitCast(:to:), so the
Swift version becomes this:
switch generic.sa_family {
case sa_family_t(AF_INET):
let ipv4 = unsafeBitCast(generic, to: sockaddr_in.self)
//...
case sa_family_t(AF_INET6):
let ipv6 = unsafeBitCast(generic, to: sockaddr_in6.self)
//...
default:
//...
}
—
Bouke
> On 12 sep. 2016, at 21:25, Bouke Haarsma <bo...@haarsma.eu> wrote:
>
> Hi all,
>
> Inside my CFSocketCallBack a pointer to a sockaddr is provided wrapped in a
> CFData structure. The sockaddr could be either a sockaddr_in (IPv4) or
> sockaddr_in6 (IPv6) struct. In order to discover which struct you’re dealing
> with, the attribute sa_family can be inspected. In C this would look
> something like this:
>
> struct sockaddr_storage sa;
>
> switch (((sockaddr*)&sa)->sa_family)
> {
> case AF_INET:
> inet_ntop(AF_INET, &(((sockaddr_in*)&sa)->sin_addr), ...);
> break;
> case AF_INET6:
> inet_ntop(AF_INET6, &(((sockaddr_in6*)&sa)->sin6_addr), ...);
> break;
> }
> (from: http://stackoverflow.com/a/13167913
> <http://stackoverflow.com/a/13167913>)
>
> Wheras to do this in Swift 3, the only way I found thus far is this:
>
> var generic = CFDataGetBytePtr(data).withMemoryRebound(to: sockaddr.self,
> capacity: 1) {
> return $0.pointee
> }
> switch generic.sa_family {
> case sa_family_t(AF_INET):
> let ipv4 = withUnsafePointer(to: &generic) {
> $0.withMemoryRebound(to: sockaddr_in.self, capacity: 1) {
> $0.pointee
> }
> }
> //...
> case sa_family_t(AF_INET6):
> let ipv6 = withUnsafePointer(to: &generic) {
> $0.withMemoryRebound(to: sockaddr_in6.self, capacity: 1) {
> $0.pointee
> }
> }
> //...
> default:
> //…
> }
>
> This looks very ugly with all the closures and ``withMemoryRebound``. Is
> there a better way to do this? I think there should be something more
> “Swifty”.
>
> —
> Bouke
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