gistfile1.txt

class Threading {
    
    static func lock<T>(_ obj: NSObject, closure: () -> [T]) -> [T] {
        objc_sync_enter(obj)
        defer { objc_sync_exit(obj) }
        return closure()
    }
    
    static func lock<T>(_ obj: NSObject, closure: () -> [T]?) -> [T]? {
        objc_sync_enter(obj)
        defer { objc_sync_exit(obj) }
        return closure()
    }
    
    static func lock<T>(_ obj: NSObject, closure: () -> T) -> T {
        objc_sync_enter(obj)
        defer { objc_sync_exit(obj) }
        return closure()
    }
    
    static func lock<T>(_ obj: NSObject, closure: () -> T?) -> T? {
        objc_sync_enter(obj)
        defer { objc_sync_exit(obj) }
        return closure()
    }
    
    static func lock(_ obj: NSObject, closure: () -> ()) {
        objc_sync_enter(obj)
        defer { objc_sync_exit(obj) }
        closure()
    }
}