bjoernager/rust
bjoernager/rust
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This commit is contained in:
Jack Huey 2020-10-11 17:14:07 -04:00
parent dd5c9bf139
commit 11d62aa284
4 changed files with 36 additions and 13 deletions
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14
compiler/rustc_middle/src/ty/mod.rs
View file

@ -1056,9 +1056,21 @@ impl<'tcx> Predicate<'tcx> {
}
}
/// Converts this to a `Binder<PredicateAtom<'tcx>>`. If the value was an
/// `Atom`, then it is not allowed to contain escaping bound vars.
pub fn bound_atom(self, _tcx: TyCtxt<'tcx>) -> Binder<PredicateAtom<'tcx>> {
match self.kind() {
&PredicateKind::ForAll(binder) => binder,
&PredicateKind::Atom(atom) => {
assert!(!atom.has_escaping_bound_vars());
Binder::dummy(atom)
}
}
}
/// Allows using a `Binder<PredicateAtom<'tcx>>` even if the given predicate previously
/// contained unbound variables by shifting these variables outwards.
pub fn bound_atom(self, tcx: TyCtxt<'tcx>) -> Binder<PredicateAtom<'tcx>> {
pub fn bound_atom_with_opt_escaping(self, tcx: TyCtxt<'tcx>) -> Binder<PredicateAtom<'tcx>> {
match self.kind() {
&PredicateKind::ForAll(binder) => binder,
&PredicateKind::Atom(atom) => Binder::wrap_nonbinding(tcx, atom),

2
compiler/rustc_middle/src/ty/print/pretty.rs
View file

@ -618,7 +618,7 @@ pub trait PrettyPrinter<'tcx>:
// may contain unbound variables. We therefore do this manually.
//
// FIXME(lcnr): Find out why exactly this is the case :)
let bound_predicate = predicate.bound_atom(self.tcx());
let bound_predicate = predicate.bound_atom_with_opt_escaping(self.tcx());
if let ty::PredicateAtom::Trait(pred, _) = bound_predicate.skip_binder() {
let trait_ref = bound_predicate.map_bound(|_| pred.trait_ref);
// Don't print +Sized, but rather +?Sized if absent.