Enum MembershipError 

pub enum MembershipError {
    NoSession(BufferId),
    SlotOutOfRange {
        slot: usize,
        arity: usize,
    },
    NotParticipant(BufferId),
    EngineRejected(DiffEngineError),
}

D.8.d (2026-05-31): errors the subsystem’s membership API returns when mutating a session’s participant set. Distinct from [DiffEngineError] (which is the engine crate’s surface) so callers don’t have to import lattice_diff just to pattern-match on add_participant failures. The engine’s cap on arity (N ≥ 4 rejected in v1) surfaces here as EngineRejected(DiffEngineError::Unsupported{...}).

Variants

NoSession(BufferId)

SlotOutOfRange

Fields

slot: usize

arity: usize

NotParticipant(BufferId)

EngineRejected(DiffEngineError)

Trait Implementations

impl Debug for MembershipError

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

Formats the value using the given formatter.

impl Display for MembershipError

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

Formats the value using the given formatter.

impl Error for MembershipError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<DiffEngineError> for MembershipError

fn from(source: DiffEngineError) -> Self

Converts to this type from the input type.