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Remove bound_{explicit,}_item_bounds

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This commit is contained in:
Michael Goulet 2023-01-03 05:01:17 +00:00
parent e1533a26f7
commit 90df86f474
6 changed files with 40 additions and 64 deletions
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48
compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
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@ -673,40 +673,34 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
let tcx = self.infcx.tcx;
// Find out if the predicates show that the type is a Fn or FnMut
let find_fn_kind_from_did = |predicates: ty::EarlyBinder<
&[(ty::Predicate<'tcx>, Span)],
>,
substs| {
predicates.0.iter().find_map(|(pred, _)| {
let pred = if let Some(substs) = substs {
predicates.rebind(*pred).subst(tcx, substs).kind().skip_binder()
} else {
pred.kind().skip_binder()
};
if let ty::PredicateKind::Clause(ty::Clause::Trait(pred)) = pred && pred.self_ty() == ty {
if Some(pred.def_id()) == tcx.lang_items().fn_trait() {
return Some(hir::Mutability::Not);
} else if Some(pred.def_id()) == tcx.lang_items().fn_mut_trait() {
return Some(hir::Mutability::Mut);
}
let find_fn_kind_from_did = |(pred, _): (ty::Predicate<'tcx>, _)| {
if let ty::PredicateKind::Clause(ty::Clause::Trait(pred)) = pred.kind().skip_binder()
&& pred.self_ty() == ty
{
if Some(pred.def_id()) == tcx.lang_items().fn_trait() {
return Some(hir::Mutability::Not);
} else if Some(pred.def_id()) == tcx.lang_items().fn_mut_trait() {
return Some(hir::Mutability::Mut);
}
None
})
}
None
};
// If the type is opaque/param/closure, and it is Fn or FnMut, let's suggest (mutably)
// borrowing the type, since `&mut F: FnMut` iff `F: FnMut` and similarly for `Fn`.
// These types seem reasonably opaque enough that they could be substituted with their
// borrowed variants in a function body when we see a move error.
let borrow_level = match ty.kind() {
ty::Param(_) => find_fn_kind_from_did(
tcx.bound_explicit_predicates_of(self.mir_def_id().to_def_id())
.map_bound(|p| p.predicates),
None,
),
ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) => {
find_fn_kind_from_did(tcx.bound_explicit_item_bounds(*def_id), Some(*substs))
}
let borrow_level = match *ty.kind() {
ty::Param(_) => tcx
.explicit_predicates_of(self.mir_def_id().to_def_id())
.predicates
.iter()
.copied()
.find_map(find_fn_kind_from_did),
ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) => tcx
.bound_explicit_item_bounds(def_id)
.subst_iter_copied(tcx, substs)
.find_map(find_fn_kind_from_did),
ty::Closure(_, substs) => match substs.as_closure().kind() {
ty::ClosureKind::Fn => Some(hir::Mutability::Not),
ty::ClosureKind::FnMut => Some(hir::Mutability::Mut),