Struct BetterThanPhase 

pub struct BetterThanPhase<'v> { /* private fields */ }

Cross-phase “is the candidate phase better than the baseline phase on this metric?” comparator, returned by crate::vmm::VmResult::better_across_phases (pooled aggregate) and crate::vmm::VmResult::better_across_phases_cgroup (one named cgroup). The polarity-aware sibling of CrossPhaseRatio: it reads two PER-PHASE scalars (via phase_metric / phase_cgroup_metric, not a sampled series) and orients “better” from the metric’s registry-declared polarity, so the same call expresses “scheduler beats EEVDF” for a LowerBetter latency AND a HigherBetter throughput without the test author naming a direction. A missing/undirected/zero-baseline comparison is Inconclusive (never a silent pass); a non-finite value is a Fail.

Implementations

impl<'v> BetterThanPhase<'v>

pub fn better_than(self) -> &'v mut Verdict

Pass iff the candidate is STRICTLY better than the baseline per the metric’s polarity (LowerBetter: candidate < baseline; HigherBetter: candidate > baseline) — any improvement, no margin.

pub fn by_at_least(self, margin: f64) -> &'v mut Verdict

Pass iff the candidate improves on the baseline by at least margin, a FRACTION of the baseline (0.10 = 10% better): LowerBetter requires candidate <= baseline * (1 - margin), HigherBetter requires candidate >= baseline * (1 + margin). by_at_least(0.0) means “no regression” (at least as good). A zero baseline is Inconclusive (nothing to scale the fractional margin against).