Struct rustc_mir_build::thir::pattern::usefulness::UsefulnessReport

pub(crate) struct UsefulnessReport<'p, 'tcx> {
    pub(crate) arm_usefulness: Vec<(MatchArm<'p, 'tcx>, Reachability)>,
    pub(crate) non_exhaustiveness_witnesses: Vec<DeconstructedPat<'p, 'tcx>>,
}

The output of checking a match for exhaustiveness and arm reachability.

Fields

arm_usefulness: Vec<(MatchArm<'p, 'tcx>, Reachability)>

For each arm of the input, whether that arm is reachable after the arms above it.

non_exhaustiveness_witnesses: Vec<DeconstructedPat<'p, 'tcx>>

If the match is exhaustive, this is empty. If not, this contains witnesses for the lack of exhaustiveness.

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference’s “Type Layout” chapter for details on type layout guarantees.

Size: 48 bytes