Enum GraphError 

pub enum GraphError {
    Cycle,
    SelfReference,
    EdgeNotFound,
    Duplicate,
}

Errors that can arise from graph mutations.

Implementations of super::Graph choose which of these can occur: a DAG rejects Cycle, SelfReference, and Duplicate; an undirected graph rejects SelfReference and Duplicate (treated as duplicate in either ordering). EdgeNotFound is universal.

Variants

Cycle

SelfReference

EdgeNotFound

Duplicate

An active edge with the same endpoints already exists. Directed graphs reject the same source -> target ordering; undirected graphs reject either {a, b} ordering. Archived edges don’t count against this check, so re-adding after archive succeeds.

Trait Implementations

impl Clone for GraphError

fn clone(&self) -> GraphError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for GraphError

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

Formats the value using the given formatter.

impl Display for GraphError

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

Formats the value using the given formatter.

impl Eq for GraphError

impl Error for GraphError

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 GraphError

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for GraphError