Struct CancelScope 

pub struct CancelScope { /* private fields */ }

A cancellation scope owned by a subsystem.

new is the canonical replacement for the legacy cancel.unwrap_or_default() fallback — the Option<CancelToken> parent picks the branch:

• composed (Some(parent)): the scope’s token is a child of the parent, so a parent/master cancel reaches this subtree.
• standalone (None): the scope’s token is itself a fresh root (CancelToken::root); nothing above can cancel it.

Either way, the inner children handed out by token derive from one node, and cancel cancels exactly that subtree. Drop is passive: dropping a scope does not cancel its subtree; teardown is an explicit cancel() (so a composed scope never cancels a token it was handed from above).

Implementations

impl CancelScope

pub fn new(parent: Option<CancelToken>) -> Self

Build a scope from an optional parent token (the composed/standalone seam). This is a domain constructor, not a generic From conversion: the branch on parent decides ownership of the subtree root.

pub fn cancel(&self)

Cancel this scope’s subtree (the node from which inner children derive).

pub fn is_cancelled(&self) -> bool

pub fn token(&self) -> CancelToken

The scope’s token. Clone it for the subsystem’s own subtree (.child() for per-task/per-fetch tokens).

Trait Implementations

impl Debug for CancelScope

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

Formats the value using the given formatter.