omochimetaru

@swift-5.9.2 @swift-5.10.1 @swift-6.0.3 protocol P {} extension Int: @retroactive P {}

<stdin>:2:16: warning: 'retroactive' attribute does not apply; 'P' is declared in this module; this is an error in the Swift 6 language mode 1 | protocol P {} 2 | extension Int: @retroactive P {} | `- warning: 'retroactive' attribute does not apply; 'P' is declared in this module; this is an error in the Swift 6 language mode 3 |