Struct ElementScope 

pub struct ElementScope { /* private fields */ }

An open per-element budget scope. Returned by enter_element; dropping it restores every accumulator to the value it had when the scope opened.

A rayon worker blocked on a nested par_iter (faceted-brep triangulation) can steal another element job onto its own thread and run it to completion before resuming the first. The thread-locals are shared by both, so a bare begin_element in the stolen element zeroes the outer element’s total and whether the outer element trips its cap depends on scheduling. Scopes nest in stack order, so a save on entry and a restore on drop keep each element’s count its own.

The scope is not Send, so it cannot be dropped on a thread other than the one whose counters it saved (#4663):

fn assert_send<T: Send>() {}
assert_send::<ifc_lite_geometry::kernel::budget::ElementScope>();

Trait Implementations

impl Drop for ElementScope

fn drop(&mut self)

Executes the destructor for this type.