koher

@swift-6.0.3

class Animal {} class Cat: Animal {} protocol P { func foo() -> Animal } struct S: P { func foo() -> Cat { Cat() } } let s = S() print(s.foo())

exit status: 1 with

<stdin>:8:8: error: type 'S' does not conform to protocol 'P' 3 | 4 | protocol P { 5 | func foo() -> Animal | `- note: protocol requires function 'foo()' with type '() -> Animal'; add a stub for conformance 6 | } 7 | 8 | struct S: P { | `- error: type 'S' does not conform to protocol 'P' 9 | func foo() -> Cat { Cat() } | `- note: candidate has non-matching type '() -> Cat' 10 | } 11 |