Description

If you pass an array of a non-Sendable object to an actor initializer, the object is not isolated to the actor's region. Same happens with dictionaries and sets.

This only seems to affect Xcode versions of Swift. I could not reproduce this on any version of Swift since 6.0.3 in godbolt: https://godbolt.org/z/xP1KGdfTE

Reproduction

class NS { var count = 0 }
actor MyActor {
  init(_ ns: [NS]) {}
}
func hole() {
  let ns = NS()
  let actor = MyActor([ns])
  ns.count += 1  // This should fail to compile but does not
  _ = actor
}

Expected behavior

Compiler should reject code since we are accessing ns after it has been sent to the actor.

Environment

swift-driver version: 1.148.6 Apple Swift version 6.3.2 (swiftlang-6.3.2.1.103 clang-2100.1.1.101)
Target: arm64-apple-macosx26.0

Additional information

No response