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@marmelroy
Created July 19, 2016 05:55
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let queue = DispatchQueue.global(attributes: .qosUserInitiated)
let mainQueue = DispatchQueue.main
mainQueue.async {
dispatchPrecondition(condition: .notOnQueue(mainQueue))
// This code won't execute
}
queue.async {
dispatchPrecondition(condition: .onQueue(queue))
// This code will execute
}
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