No,
}
+#[derive(Debug)]
struct ConvertedBinding<'a, 'tcx> {
item_name: Ident,
kind: ConvertedBindingKind<'a, 'tcx>,
+ gen_args: &'a GenericArgs<'a>,
span: Span,
}
+#[derive(Debug)]
enum ConvertedBindingKind<'a, 'tcx> {
Equality(Ty<'tcx>),
Constraint(&'a [hir::GenericBound<'a>]),
let tcx = self.tcx();
let generics = tcx.generics_of(def_id);
+ debug!("generics: {:?}", generics);
if generics.has_self {
if generics.parent.is_some() {
ConvertedBindingKind::Constraint(bounds)
}
};
- ConvertedBinding { item_name: binding.ident, kind, span: binding.span }
+ ConvertedBinding {
+ item_name: binding.ident,
+ kind,
+ gen_args: binding.gen_args,
+ span: binding.span,
+ }
})
.collect();
dup_bindings: &mut FxHashMap<DefId, Span>,
path_span: Span,
) -> Result<(), ErrorReported> {
- let tcx = self.tcx();
-
- if !speculative {
- // Given something like `U: SomeTrait<T = X>`, we want to produce a
- // predicate like `<U as SomeTrait>::T = X`. This is somewhat
- // subtle in the event that `T` is defined in a supertrait of
- // `SomeTrait`, because in that case we need to upcast.
- //
- // That is, consider this case:
- //
- // ```
- // trait SubTrait: SuperTrait<i32> { }
- // trait SuperTrait<A> { type T; }
- //
- // ... B: SubTrait<T = foo> ...
- // ```
- //
- // We want to produce `<B as SuperTrait<i32>>::T == foo`.
-
- // Find any late-bound regions declared in `ty` that are not
- // declared in the trait-ref. These are not well-formed.
- //
- // Example:
- //
- // for<'a> <T as Iterator>::Item = &'a str // <-- 'a is bad
- // for<'a> <T as FnMut<(&'a u32,)>>::Output = &'a str // <-- 'a is ok
- if let ConvertedBindingKind::Equality(ty) = binding.kind {
- let late_bound_in_trait_ref =
- tcx.collect_constrained_late_bound_regions(&trait_ref);
- let late_bound_in_ty =
- tcx.collect_referenced_late_bound_regions(&ty::Binder::bind(ty));
- debug!("late_bound_in_trait_ref = {:?}", late_bound_in_trait_ref);
- debug!("late_bound_in_ty = {:?}", late_bound_in_ty);
+ // Given something like `U: SomeTrait<T = X>`, we want to produce a
+ // predicate like `<U as SomeTrait>::T = X`. This is somewhat
+ // subtle in the event that `T` is defined in a supertrait of
+ // `SomeTrait`, because in that case we need to upcast.
+ //
+ // That is, consider this case:
+ //
+ // ```
+ // trait SubTrait: SuperTrait<i32> { }
+ // trait SuperTrait<A> { type T; }
+ //
+ // ... B: SubTrait<T = foo> ...
+ // ```
+ //
+ // We want to produce `<B as SuperTrait<i32>>::T == foo`.
- // FIXME: point at the type params that don't have appropriate lifetimes:
- // struct S1<F: for<'a> Fn(&i32, &i32) -> &'a i32>(F);
- // ---- ---- ^^^^^^^
- self.validate_late_bound_regions(
- late_bound_in_trait_ref,
- late_bound_in_ty,
- |br_name| {
- struct_span_err!(
- tcx.sess,
- binding.span,
- E0582,
- "binding for associated type `{}` references {}, \
- which does not appear in the trait input types",
- binding.item_name,
- br_name
- )
- },
- );
- }
- }
+ debug!(
+ "add_predicates_for_ast_type_binding(hir_ref_id {:?}, trait_ref {:?}, binding {:?}, bounds {:?}",
+ hir_ref_id, trait_ref, binding, bounds
+ );
+ let tcx = self.tcx();
let candidate =
if self.trait_defines_associated_type_named(trait_ref.def_id(), binding.item_name) {
.or_insert(binding.span);
}
+ // Include substitutions for generic parameters of associated types
+ let projection_ty = candidate.map_bound(|trait_ref| {
+ let item_segment = hir::PathSegment {
+ ident: assoc_ty.ident,
+ hir_id: None,
+ res: None,
+ args: Some(binding.gen_args),
+ infer_args: false,
+ };
+
+ let substs_trait_ref_and_assoc_item = self.create_substs_for_associated_item(
+ tcx,
+ path_span,
+ assoc_ty.def_id,
+ &item_segment,
+ trait_ref.substs,
+ );
+
+ debug!(
+ "add_predicates_for_ast_type_binding: substs for trait-ref and assoc_item: {:?}",
+ substs_trait_ref_and_assoc_item
+ );
+
+ ty::ProjectionTy {
+ item_def_id: assoc_ty.def_id,
+ substs: substs_trait_ref_and_assoc_item,
+ }
+ });
+
+ if !speculative {
+ // Find any late-bound regions declared in `ty` that are not
+ // declared in the trait-ref or assoc_ty. These are not well-formed.
+ //
+ // Example:
+ //
+ // for<'a> <T as Iterator>::Item = &'a str // <-- 'a is bad
+ // for<'a> <T as FnMut<(&'a u32,)>>::Output = &'a str // <-- 'a is ok
+ if let ConvertedBindingKind::Equality(ty) = binding.kind {
+ let late_bound_in_trait_ref =
+ tcx.collect_constrained_late_bound_regions(&projection_ty);
+ let late_bound_in_ty =
+ tcx.collect_referenced_late_bound_regions(&ty::Binder::bind(ty));
+ debug!("late_bound_in_trait_ref = {:?}", late_bound_in_trait_ref);
+ debug!("late_bound_in_ty = {:?}", late_bound_in_ty);
+
+ // FIXME: point at the type params that don't have appropriate lifetimes:
+ // struct S1<F: for<'a> Fn(&i32, &i32) -> &'a i32>(F);
+ // ---- ---- ^^^^^^^
+ self.validate_late_bound_regions(
+ late_bound_in_trait_ref,
+ late_bound_in_ty,
+ |br_name| {
+ struct_span_err!(
+ tcx.sess,
+ binding.span,
+ E0582,
+ "binding for associated type `{}` references {}, \
+ which does not appear in the trait input types",
+ binding.item_name,
+ br_name
+ )
+ },
+ );
+ }
+ }
+
match binding.kind {
ConvertedBindingKind::Equality(ref ty) => {
// "Desugar" a constraint like `T: Iterator<Item = u32>` this to
//
// `<T as Iterator>::Item = u32`
bounds.projection_bounds.push((
- candidate.map_bound(|trait_ref| ty::ProjectionPredicate {
- projection_ty: ty::ProjectionTy::from_ref_and_name(
- tcx,
- trait_ref,
- binding.item_name,
- ),
- ty,
+ projection_ty.map_bound(|projection_ty| {
+ debug!(
+ "add_predicates_for_ast_type_binding: projection_ty {:?}, substs: {:?}",
+ projection_ty, projection_ty.substs
+ );
+ ty::ProjectionPredicate { projection_ty, ty }
}),
binding.span,
));
//
// Calling `skip_binder` is okay, because `add_bounds` expects the `param_ty`
// parameter to have a skipped binder.
- let param_ty = tcx.mk_projection(assoc_ty.def_id, candidate.skip_binder().substs);
+ let param_ty =
+ tcx.mk_projection(assoc_ty.def_id, projection_ty.skip_binder().substs);
self.add_bounds(param_ty, ast_bounds, bounds);
}
}
&generics.params[..],
visitor.0,
true,
+ true
);
}
projects / rust.git / blobdiff