ignore uncaptured lifetimes when checking opaques

This commit is contained in:
Ali MJ Al-Nasrawy 2024-03-18 08:33:24 +00:00
parent 92f40b8059
commit 4e1999d387
11 changed files with 183 additions and 17 deletions

View file

@ -832,6 +832,38 @@ pub struct OpaqueTypeKey<'tcx> {
pub args: GenericArgsRef<'tcx>,
}
impl<'tcx> OpaqueTypeKey<'tcx> {
pub fn iter_captured_args(
self,
tcx: TyCtxt<'tcx>,
) -> impl Iterator<Item = (usize, GenericArg<'tcx>)> {
std::iter::zip(self.args, tcx.variances_of(self.def_id)).enumerate().filter_map(
|(i, (arg, v))| match (arg.unpack(), v) {
(_, ty::Invariant) => Some((i, arg)),
(ty::GenericArgKind::Lifetime(_), ty::Bivariant) => None,
_ => bug!("unexpected opaque type arg variance"),
},
)
}
pub fn fold_captured_lifetime_args(
self,
tcx: TyCtxt<'tcx>,
mut f: impl FnMut(Region<'tcx>) -> Region<'tcx>,
) -> Self {
let Self { def_id, args } = self;
let args = std::iter::zip(args, tcx.variances_of(def_id)).map(|(arg, v)| {
match (arg.unpack(), v) {
(ty::GenericArgKind::Lifetime(_), ty::Bivariant) => arg,
(ty::GenericArgKind::Lifetime(lt), _) => f(lt).into(),
_ => arg,
}
});
let args = tcx.mk_args_from_iter(args);
Self { def_id, args }
}
}
#[derive(Copy, Clone, Debug, TypeFoldable, TypeVisitable, HashStable, TyEncodable, TyDecodable)]
pub struct OpaqueHiddenType<'tcx> {
/// The span of this particular definition of the opaque type. So