_modfiy lock

lock.swift

@propertyWrapper
public final class ThreadSafe<Root> {
    private let lock = OSUnfairLock()

    private var value: Root

    public init(wrappedValue: Root) {
        self.value = wrappedValue
    }

    public var projectedValue: ThreadSafe<Root> { self }

    public var wrappedValue: Root {
        get {
            self.lock.lock()
            defer {
                self.lock.unlock()
            }
            return self.value
        }
        _modify {
            self.lock.lock()
            yield &self.value
            self.lock.unlock()
        }
    }
}