static hashmap container

PropertyData.swift

private struct PropertyData {
    static private let accessQueue = DispatchQueue(label: "SynchronizedPropertyDataAccess", attributes: .concurrent)
    static private var property = [Weak<AnyObject>: [Any]]()

    static func memoryClean() {
        Self.accessQueue.async(flags: .barrier) {
            property = property.filter({$0.key.wrappedValue != nil})
        }
    }

    static func get<T>(_ key: Weak<AnyObject>) -> T? {
        Self.memoryClean()
        var res: T?
        self.accessQueue.sync {
            res = Self.property[key]?.first { $0 is T } as? T
        }
        return res
    }

    static func set(_ key: Weak<AnyObject>, value: Any) {
        Self.memoryClean()
        Self.accessQueue.async(flags: .barrier) {
            Self.property[key, default: []] += [value]
        }
    }
}