Struct PhaseGuard 

pub struct PhaseGuard { /* private fields */ }

RAII scope guard for the ACTIVE_PHASE thread-local. Install at scenario-driver run_step entry; the guard’s Drop restores the prior phase label, supporting cleanly-nested scenario dispatch (sub-scenarios layer over a parent’s phase context without leaking).

let _guard = PhaseGuard::install_step(0); // Step[0] → "Step[0]"
// ... apply_ops + hold, every assert constructed here stamps
//     phase = Some("Step[0]") automatically ...
// drop on scope exit restores the prior label (BASELINE outside
// any nested Step).

Implementations

impl PhaseGuard

pub fn install(label: impl Into<Cow<'static, str>>) -> Self

Install label as the active phase. Captures the previously-active label for restoration on Drop. Use Self::install_step / Self::install_baseline for the scenario-driver call sites — they produce the standard "Step[k]" / "BASELINE" labels matching the rest of the pipeline.

pub fn install_step(zero_indexed: u16) -> Self

Convenience: install the "Step[k]" label for the zero_indexed-th scenario Step. Matches the label PhaseBucket embeds + the Phase::step display (Step[0], Step[1], …).

pub fn install_baseline() -> Self

Convenience: install the "BASELINE" label for the pre-first-Step settle window. Matches the label PhaseBucket uses for step_index = 0.

Trait Implementations

impl Drop for PhaseGuard

fn drop(&mut self)

Executes the destructor for this type.