Use associated_type_bounds where applicable - closes #61738

src/librustc/lib.rs

@@ -61,6 +61,7 @@
 #![feature(proc_macro_hygiene)]
 #![feature(log_syntax)]
 #![feature(mem_take)]
+#![feature(associated_type_bounds)]
 
 #![recursion_limit="512"]
 

src/librustc/traits/select.rs

@@ -3901,7 +3901,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         // each predicate must be preceded by the obligations required
         // to normalize it.
         // for example, if we have:
-        //    impl<U: Iterator, V: Iterator<Item=U>> Foo for V where U::Item: Copy
+        //    impl<U: Iterator<Item: Copy>, V: Iterator<Item = U>> Foo for V
         // the impl will have the following predicates:
         //    <V as Iterator>::Item = U,
         //    U: Iterator, U: Sized,

src/librustc/traits/structural_impls.rs

@@ -980,8 +980,7 @@ EnumTypeFoldableImpl! {
         (chalk_engine::DelayedLiteral::Negative)(a),
         (chalk_engine::DelayedLiteral::Positive)(a, b),
     } where
-        C: chalk_engine::context::Context + Clone,
-        C::CanonicalConstrainedSubst: TypeFoldable<'tcx>,
+        C: chalk_engine::context::Context<CanonicalConstrainedSubst: TypeFoldable<'tcx>> + Clone,
 }
 
 EnumTypeFoldableImpl! {
@@ -989,8 +988,7 @@ EnumTypeFoldableImpl! {
         (chalk_engine::Literal::Negative)(a),
         (chalk_engine::Literal::Positive)(a),
     } where
-        C: chalk_engine::context::Context + Clone,
-        C::GoalInEnvironment: Clone + TypeFoldable<'tcx>,
+        C: chalk_engine::context::Context<GoalInEnvironment: Clone + TypeFoldable<'tcx>> + Clone,
 }
 
 CloneTypeFoldableAndLiftImpls! {

src/librustc/ty/context.rs

@@ -2663,8 +2663,8 @@ impl<'tcx> TyCtxt<'tcx> {
                         unsafety: hir::Unsafety,
                         abi: abi::Abi)
         -> <I::Item as InternIteratorElement<Ty<'tcx>, ty::FnSig<'tcx>>>::Output
-        where I: Iterator,
-              I::Item: InternIteratorElement<Ty<'tcx>, ty::FnSig<'tcx>>
+    where
+        I: Iterator<Item: InternIteratorElement<Ty<'tcx>, ty::FnSig<'tcx>>>,
     {
         inputs.chain(iter::once(output)).intern_with(|xs| ty::FnSig {
             inputs_and_output: self.intern_type_list(xs),

src/librustc/ty/layout.rs

@@ -2027,9 +2027,9 @@ impl ty::query::TyCtxtAt<'tcx> {
 
 impl<'tcx, C> TyLayoutMethods<'tcx, C> for Ty<'tcx>
 where
-    C: LayoutOf<Ty = Ty<'tcx>> + HasTyCtxt<'tcx>,
-    C::TyLayout: MaybeResult<TyLayout<'tcx>>,
-    C: HasParamEnv<'tcx>,
+    C: LayoutOf<Ty = Ty<'tcx>, TyLayout: MaybeResult<TyLayout<'tcx>>>
+        + HasTyCtxt<'tcx>
+        + HasParamEnv<'tcx>,
 {
     fn for_variant(this: TyLayout<'tcx>, cx: &C, variant_index: VariantIdx) -> TyLayout<'tcx> {
         let details = match this.variants {

src/librustc/ty/query/on_disk_cache.rs

@@ -1055,9 +1055,8 @@ fn encode_query_results<'a, 'tcx, Q, E>(
     query_result_index: &mut EncodedQueryResultIndex,
 ) -> Result<(), E::Error>
 where
-    Q: super::config::QueryDescription<'tcx>,
+    Q: super::config::QueryDescription<'tcx, Value: Encodable>,
     E: 'a + TyEncoder,
-    Q::Value: Encodable,
 {
     let desc = &format!("encode_query_results for {}",
         ::std::any::type_name::<Q>());