let hir_id = tcx.hir().local_def_id_to_hir_id(def_id);
let cause = ObligationCause::misc(span, hir_id);
for ty in assumed_wf_types {
- implied_bounds.insert(ty);
+ // FIXME(@lcnr): rustc currently does not check wf for types
+ // pre-normalization, meaning that implied bounds are sometimes
+ // incorrect. See #100910 for more details.
+ //
+ // Not adding the unnormalized types here mostly fixes that, except
+ // that there are projections which are still ambiguous in the item definition
+ // but do normalize successfully when using the item, see #98543.
+ //
+ // Anyways, I will hopefully soon change implied bounds to make all of this
+ // sound and then uncomment this line again.
+
+ // implied_bounds.insert(ty);
let normalized = self.normalize(cause.clone(), param_env, ty);
implied_bounds.insert(normalized);
}
--- /dev/null
+struct Foo<T>(T);
+
+trait GoodBye {
+ type Forget;
+}
+impl<T> GoodBye for T {
+ type Forget = ();
+}
+
+trait NeedsWf<'a, 'b> {
+ type Assoc;
+}
+
+impl<'a, 'b> NeedsWf<'a, 'b> for Foo<<&'a &'b () as GoodBye>::Forget> {
+ type Assoc = &'a &'b ();
+ //~^ ERROR in type `&'a &'b ()`, reference has a longer lifetime than the data it references
+}
+
+fn needs_wf<'a, 'b, T: NeedsWf<'a, 'b>>() {}
+
+fn foo<'a: 'a, 'b: 'b>(_: &'b String) {
+ needs_wf::<'a, 'b, Foo<()>>();
+}
+
+fn main() {
+ let x = String::from("hello");
+ foo::<'static, '_>(&x);
+}
--- /dev/null
+error[E0491]: in type `&'a &'b ()`, reference has a longer lifetime than the data it references
+ --> $DIR/impl-header-unnormalized-types.rs:15:18
+ |
+LL | type Assoc = &'a &'b ();
+ | ^^^^^^^^^^
+ |
+note: the pointer is valid for the lifetime `'a` as defined here
+ --> $DIR/impl-header-unnormalized-types.rs:14:6
+ |
+LL | impl<'a, 'b> NeedsWf<'a, 'b> for Foo<<&'a &'b () as GoodBye>::Forget> {
+ | ^^
+note: but the referenced data is only valid for the lifetime `'b` as defined here
+ --> $DIR/impl-header-unnormalized-types.rs:14:10
+ |
+LL | impl<'a, 'b> NeedsWf<'a, 'b> for Foo<<&'a &'b () as GoodBye>::Forget> {
+ | ^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0491`.