Enum ReplayPolicy 

#[non_exhaustive]
pub enum ReplayPolicy<'a> {
    Guard(&'a dyn ReplayGuard),
    NotConsequential,
}

How a consumer applies SPEC §7.2 item 11 in consume_inbound.

The choice is required rather than defaulted, for the reason PayloadPolicy is: a consumer should decide knowingly whether the task it implements is consequential, not discover after an incident that it never kept a record.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Guard(&'a dyn ReplayGuard)

Apply item 11 using this guard. The correct setting for any consequential specification.

NotConsequential

Do not keep a duplicate-execution record.

Conformant only where the task is not consequential (§2), or where the Trust Task specification “explicitly declares repeated execution safe and intended” — the narrow disapplication item 11 allows, which is a property of the operation and not of the consumer’s convenience.