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// RUN: %target-run-simple-swift | %FileCheck %s
// REQUIRES: executable_test
// REQUIRES: objc_interop
// rdar://problem/19060227
import Foundation
class ObservedValue: NSObject {
@objc dynamic var amount = 0
}
class ValueObserver: NSObject {
private var observeContext = 0
let observedValue: ObservedValue
init(value: ObservedValue) {
observedValue = value
super.init()
observedValue.addObserver(self, forKeyPath: "amount", options: .new, context: &observeContext)
}
deinit {
observedValue.removeObserver(self, forKeyPath: "amount")
}
override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
if context == &observeContext {
if let change_ = change {
if let amount = change_[.newKey] as? Int {
print("Observed value updated to \(amount)")
}
}
}
}
}
let value = ObservedValue()
value.amount = 42
let observer = ValueObserver(value: value)
// CHECK: updated to 43
value.amount += 1
// CHECK: amount: 43
dump(value)
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