Struct Extensions 

pub struct Extensions { /* private fields */ }

Type-keyed cross-cutting state attached to an crate::ExecutionContext. Operators add their own values via crate::ExecutionContext::add_extension and read them back via crate::ExecutionContext::extension.

Cloning is cheap — internally an Arc over the underlying map, so cloning a context that already carries extensions does not duplicate the entries.

Implementations

impl Extensions

pub fn new() -> Self

Create an empty Extensions. Equivalent to Default::default.

pub fn len(&self) -> usize

Number of entries currently stored. Diagnostic helper — production code rarely cares.

pub fn is_empty(&self) -> bool

True when the carrier has no entries.

pub fn get<T>(&self) -> Option<Arc<T>>

where T: Send + Sync + 'static,

Look up the entry registered for T. Returns None when no value of that type has been inserted.

The returned Arc<T> is a fresh refcount bump — the caller can hold it across awaits without keeping the ExecutionContext alive.

pub fn contains<T>(&self) -> bool

where T: Send + Sync + 'static,

True when the carrier has an entry for T.

Trait Implementations

impl Clone for Extensions

fn clone(&self) -> Extensions

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Extensions

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

Formats the value using the given formatter.

impl Default for Extensions

fn default() -> Extensions

Returns the “default value” for a type.