Swift postfix function like Linux Shell background operator

gistfile1.swift

// define Swift postfix function like Linux Shell background operator
operator postfix & {}
@postfix func & (backgroundClosure: () -> ()) {
    dispatch_async(_queue) {
        backgroundClosure()
    }
}

// testing log function
func log(message: String)
{
    let main = NSThread.currentThread().isMainThread
    let name = main ? "[main]" : "[back]"
    println("\(name) \(message)")
}

// let's try
var a_process = { log("my background thread") }
        
a_process&

// it will log => [back] my background thread

// inspired by http://ijoshsmith.com/2014/07/05/custom-threading-operator-in-swift/