Enum NotAttemptable 

#[non_exhaustive]
pub enum NotAttemptable {
    SiteReturnsStreamAction,
    SiteReturnsAction,
    NoConstructor,
    KindNotDefinedAtThisSite,
}

Why a Support::NotAttemptable cell cannot be reached.

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.

SiteReturnsStreamAction

This site’s hook method returns StreamAction, and kind names a content action.

SiteReturnsAction

This site’s hook method returns Action, and kind names a stream action.

NoConstructor

No value of Action or StreamAction carries this kind to this site, so nothing here can be attempted.

KindNotDefinedAtThisSite

The kind names a unit this site does not carry, so no value can bring it here even though the expression that would carry it is well-typed at this site under a different kind.

The only occupant is ActionKind::ReplaceObject at any site but Site::Object: Action::Replace(b) typechecks at Site::Control and Site::Datagram, but there it is the ActionKind::Replace attempt — a control frame is not an object. The accompanying refusal is Refusal::WrongSite, the same refusal the attemptable ReplaceObject × Object cell really emits, so a reader comparing the table against a run sees one consistent answer.

Trait Implementations

impl Clone for NotAttemptable

fn clone(&self) -> NotAttemptable

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for NotAttemptable

impl Debug for NotAttemptable

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for NotAttemptable

impl PartialEq for NotAttemptable

fn eq(&self, other: &NotAttemptable) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for NotAttemptable