[DispatchQueue+isMain] Determine if the current GCD Queue is the main queue #swift

DispatchQueue+isMain.swift

extension DispatchQueue {
    fileprivate static let mainQueueKey = DispatchSpecificKey<()>()

    static func configureMainQueue() {
        main.setSpecific(key: mainQueueKey, value: ())
    }
}

public extension DispatchQueue {
    /// Easy and safe way of checking if the current queue is the main queue
    static var isMain: Bool {
        return getSpecific(key: mainQueueKey) != nil
    }

    /// Easy and safe way of checking if the current queue is the main queue
    var isMain: Bool {
        return getSpecific(key: DispatchQueue.mainQueueKey) != nil
    }
}