Struct TokenRegistry 

pub struct TokenRegistry<T> { /* private fields */ }

Waiting closures keyed by token: the shape behind every platform completion that crosses an FFI boundary as a number (docs/bridge.md “Callbacks”).

Rules that make it safe to hand a token to code in another language:

• Register before the call goes out. A platform may complete synchronously, or fail before returning; a slot that exists first is found either way.
• An unknown token is a no-op. A late, duplicate, or cancelled completion finds nothing and does nothing.
• Deliver outside the lock. The closure may register a new token or drop a handle; the registry is never held while it runs.

const-constructible, so a generated static can own one per declaration.

Implementations

impl<T> TokenRegistry<T>

pub const fn new() -> Self

An empty registry.

pub fn insert(&self, cb: impl FnOnce(T) + Send + 'static) -> u64

Store cb under a fresh token.

pub fn complete(&self, token: u64, value: T) -> bool

Remove the closure for token and run it with value. false when no closure waits under that token (completed, cancelled, or never registered).

pub fn remove(&self, token: u64) -> bool

Forget token without running its closure: the waiting side gave up.

pub fn contains(&self, token: u64) -> bool

Whether a closure still waits under token.

pub fn len(&self) -> usize

How many closures wait, for tests and diagnostics.

pub fn is_empty(&self) -> bool

Whether nothing waits.

Trait Implementations

impl<T> Default for TokenRegistry<T>

fn default() -> Self

Returns the “default value” for a type.