reachability function in swift 4 xcode 9

Question

I want to make reachability function in xcode 9 but I got this error when do reachability class, how to fix this error? "Value of type 'SCNetworkReachability?' has no member 'takeRetainedValue'". Here is my code

import UIKit
import Foundation
import SystemConfiguration

public class reachability {

    class func isConnectedToNetwork() -> Bool {

        var zeroAddress = sockaddr_in(sin_len: 0, sin_family: 0, sin_port: 0, sin_addr: in_addr(s_addr: 0), sin_zero: (0, 0, 0, 0, 0, 0, 0, 0))
        zeroAddress.sin_len = UInt8(MemoryLayout.size(ofValue: zeroAddress))
        zeroAddress.sin_family = sa_family_t(AF_INET)


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

        var flags: SCNetworkReachabilityFlags = SCNetworkReachabilityFlags(rawValue: 0)
        if SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) == 0 {
            return false
        }

        let isReachable = (flags.rawValue & UInt32(kSCNetworkFlagsReachable)) != 0
        let needsConnection = (flags.rawValue & UInt32(kSCNetworkFlagsConnectionRequired)) != 0

        return (isReachable && !needsConnection) ? true : false
    }

}

Answer 1

There are many errors when compiling the code in Swift 4.

A Swift 4 compatible version is (please name classes with a starting uppercase letter)

public class Reachability {

    class func isConnectedToNetwork() -> Bool {

        var zeroAddress = sockaddr()
        zeroAddress.sa_len = UInt8(MemoryLayout<sockaddr>.size)
        zeroAddress.sa_family = sa_family_t(AF_INET)

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

        var flags = SCNetworkReachabilityFlags()
        guard SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) else { return false }

        return flags.contains(.reachable) && !flags.contains(.connectionRequired)
    }

}