Struct StreamCell 

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

Versioned, thread-safe cell holding the latest value of a stream.

A StreamCell collapses a stream to its most recent value with optimistic concurrency: each successful write bumps a version counter, and writers must present the version they observed to commit. It is the shared “current value” handoff point between a producing stream and its consumers.

Examples

use sim_lib_stream_combinators::stream_cell;

let cell = stream_cell("first".to_owned());
let snapshot = cell.get().unwrap();
assert_eq!(snapshot.version, 0);

let next = cell.set("second".to_owned(), snapshot.version).unwrap();
assert_eq!(next, 1);

// A stale version is rejected.
assert!(cell.set("third".to_owned(), snapshot.version).is_err());
assert_eq!(cell.get().unwrap().value, "second");

Implementations

impl<T> StreamCell<T>

pub fn new(value: T) -> Self

Creates a cell holding value at version 0.

impl<T: Clone> StreamCell<T>

pub fn get(&self) -> Result<CellSnapshot<T>>

Reads a versioned snapshot of the current cell value.

pub fn set(&self, value: T, expected_version: u64) -> Result<u64>

Writes value only if expected_version matches the current version.

On success the version is bumped and the new version is returned; a mismatch leaves the cell untouched and returns an error.