Struct ClaimBetter 

pub struct ClaimBetter<'a> { /* private fields */ }

Direct-claim “is this candidate better than this baseline on a registered metric?” comparator, returned by Verdict::claim_better. The polarity-aware sibling of crate::vmm::VmResult::better_across_phases for the case where the test already HOLDS two scalar values (not two phases): it orients “better” from the metric’s registry-declared polarity, so the SAME call expresses “candidate beats baseline” for a LowerBetter latency AND a HigherBetter throughput without the test author naming a direction. A metric with no lower/higher-better polarity (TargetValue / Unknown / Informational / an unregistered or typo’d name) is INCONCLUSIVE (never a silent pass); a non-finite endpoint is a Fail.

Implementations

impl<'a> ClaimBetter<'a>

pub fn than(self, baseline: f64) -> &'a mut Verdict

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

pub fn than_by(self, baseline: f64, margin: f64) -> &'a mut Verdict

Pass iff the candidate improves on baseline by at least margin, a FRACTION of the baseline (0.10 = 10% better). than_by(b, 0.0) means “no regression” (at least as good). A zero baseline is Inconclusive (nothing to scale the margin against).