Enum OutletAttachError 

pub enum OutletAttachError {
    SelfAttachment,
    Cycle,
    AlreadyAttached,
}

Why a nested outlet attachment was rejected.

Rejection happens before any mutation, so a failed attach leaves both outlets exactly as they were. The topology is a forest by design — like back dispatch it must terminate, but unlike back dispatch (which follows a single active chain and can share children) cascade driving visits every registered child, so one child under two parents would drive twice per frame.

Variants

SelfAttachment

An outlet cannot nest inside itself.

Cycle

The child already reaches the parent through nested attachments, so the edge would close a directed cycle and cascade driving could recurse through it forever.

AlreadyAttached

The child is already attached to a different live parent. Detach it explicitly first: cascade driving follows registration, so a second parent would drive the same outlet twice per frame.

Trait Implementations

impl Clone for OutletAttachError

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for OutletAttachError

impl Debug for OutletAttachError

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

Formats the value using the given formatter.

impl Display for OutletAttachError

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

Formats the value using the given formatter.

impl Eq for OutletAttachError

impl Error for OutletAttachError

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 PartialEq for OutletAttachError

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for OutletAttachError