// RUN: %target-typecheck-verify-swift -swift-version 4

// Ensure that we do not select the unavailable failable init as the
// only solution and then fail to typecheck.
protocol P {}

class C : P {
  @available(swift, obsoleted: 4)
  public init?(_ c: C) {
  }

  public init<T : P>(_ c: T) {}
}

func f(c: C) {
  let _: C? = C(c)
}