[][src]Function rustc_mir::hair::pattern::_match::is_useful_specialized

fn is_useful_specialized<'p, 'a: 'p, 'tcx: 'a>(
    cx: &mut MatchCheckCtxt<'a, 'tcx>,
    Matrix: &Matrix<'p, 'tcx>,
    v: &[&'p Pattern<'tcx>],
    ctor: Constructor<'tcx>,
    lty: Ty<'tcx>,
    witness: WitnessPreference
) -> Usefulness<'tcx>
🔬 This is a nightly-only experimental API. (rustc_private)

this crate is being loaded from the sysroot, an unstable location; did you mean to load this crate from crates.io via Cargo.toml instead?

A shorthand for the U(S(c, P), S(c, q)) operation from the paper. I.e. is_useful applied to the specialised version of both the pattern matrix P and the new pattern q.