Function rustc_pattern_analysis::usefulness::compute_match_usefulness

pub fn compute_match_usefulness<'p, Cx: TypeCx>(
    cx: MatchCtxt<'_, 'p, Cx>,
    arms: &[MatchArm<'p, Cx>],
    scrut_ty: Cx::Ty,
    scrut_validity: ValidityConstraint
) -> Result<UsefulnessReport<'p, Cx>, Cx::Error>

Computes whether a match is exhaustive and which of its arms are useful.