Why can I mark a Sendable value sending

[mattmassicotte]

Description

It's possible this is expected, but it seems to me like maybe this should be a warning?

Reproduction

struct ThisIsSendable: Sendable {
}

// feels redundant, no?
func acceptStuff(_ value: sending ThisIsSendable) {
}

Expected behavior

I would expect a warning. The sending is redundant. And if something changed such that it became necessary, that would immeidately be surfaced within the function body as an error.

Environment

Apple Swift version 6.0-dev (LLVM 5f87d6ee2f8c800, Swift 5c01ca1)
Target: arm64-apple-macosx14.0

Additional information

No response

[ktoso]

That feels redundant indeed, sending a Sendable type doesn't really do anything to the Sendable type, it is free to be sent around freely after all.

[hborla]

IMO this should result in a compiler warning that sending has no effect on a type conforming to Sendable

[Androp0v]

Can I get this assigned? I already opened a PR (#74849)