| // RUN: %target-typecheck-verify-swift -enable-objc-interop -swift-version 5 | |
| @objc protocol Opt { | |
| @objc optional func f(callback: @escaping () -> ()) | |
| } | |
| class Conforms : Opt { | |
| private func f(callback: () -> ()) {} | |
| // expected-error@-1 {{method 'f(callback:)' must be declared internal because it matches a requirement in internal protocol 'Opt'}} | |
| // expected-note@-2 {{mark the instance method as 'internal' to satisfy the requirement}} | |
| } | |
| func g(x: Conforms) { | |
| _ = x.f(callback: {}) | |
| } |