Cannot opt back into checked Sendable conformance

[mattmassicotte]

Description

I was surprised to see that I cannot opt back into a checked Sendable conformance to silence this warning.

Reproduction

class A: @unchecked Sendable {
}

final class B: A, Sendable {
}

Expected behavior

I would expect this code to be warning free.

Environment

Apple Swift version 6.0-dev (LLVM 6e13b8be259f20f, Swift 372de46)
Target: arm64-apple-macosx14.0

Additional information

No response

[hborla]

Yeah, I don't know how to actually allow this, because the compiler cannot check anything that's inherited from the superclass, so you'd get a false sense of promise that your type really has a checked Sendable conformance.

[mattmassicotte]

My naive assumption was that the compiler could perform the same checking as it would if the superclass was checked-Sendable.