PreferSendable [rule] v0.1.0

Under Swift 6 strict concurrency, any value passed across an actor boundary, into a detached task, or stored in @Sendable state must conform to Sendable. Public APIs benefit from being Sendable-by-default: it lets clients use the type freely from any isolation context. For value types with Sendable stored properties the conformance is automatic; for reference types it requires the type to be immutable, an actor, or to enforce its own synchronisation.

Checks

• Public structs / enums / tuples with Sendable stored properties declare : Sendable (or are inferred Sendable in Swift 6 frozen modes).
• Public final classes that hold only let-properties of Sendable types declare : Sendable.
• Reference types that mutate internal state across threads use actor rather than class + lock whenever possible.
• Where a class cannot be made Sendable, the API documents the isolation requirement and any escape hatch (@unchecked Sendable paired with a comment justifying the synchronisation discipline).
• Closures stored or escaped across actor boundaries are typed @Sendable.

Label

Public types crossing concurrency boundaries are Sendable; document why anything is not

PreferSendable [rule] v0.1.0

Under Swift 6 strict concurrency, any value passed across an actor boundary, into a detached task, or stored in @Sendable state must conform to Sendable. Public APIs benefit from being Sendable-by-default: it lets clients use the type freely from any isolation context. For value types with Sendable stored properties the conformance is automatic; for reference types it requires the type to be immutable, an actor, or to enforce its own synchronisation.

Checks

• Public structs / enums / tuples with Sendable stored properties declare : Sendable (or are inferred Sendable in Swift 6 frozen modes).
• Public final classes that hold only let-properties of Sendable types declare : Sendable.
• Reference types that mutate internal state across threads use actor rather than class + lock whenever possible.
• Where a class cannot be made Sendable, the API documents the isolation requirement and any escape hatch (@unchecked Sendable paired with a comment justifying the synchronisation discipline).
• Closures stored or escaped across actor boundaries are typed @Sendable.

Label

Public types crossing concurrency boundaries are Sendable; document why anything is not

Label

Public types crossing concurrency boundaries are Sendable; document why anything is not