add eq constraints on associated constants

src/librustdoc/clean/mod.rs

@@ -2117,7 +2117,8 @@ impl Clean<TypeBindingKind> for hir::TypeBindingKind<'_> {
             hir::TypeBindingKind::Equality { ref ty } => {
                 TypeBindingKind::Equality { ty: ty.clean(cx) }
             }
-            hir::TypeBindingKind::Constraint { bounds } => TypeBindingKind::Constraint {
+            hir::TypeBindingKind::Const { c: _ } => todo!(),
+            hir::TypeBindingKind::Constraint { ref bounds } => TypeBindingKind::Constraint {
                 bounds: bounds.iter().filter_map(|b| b.clean(cx)).collect(),
             },
         }

src/test/ui/associated-consts/assoc-const.rs

@@ -0,0 +1,14 @@
+// run-pass
+
+pub trait Foo {
+  const N: usize;
+}
+
+pub struct Bar;
+
+impl Foo for Bar {
+  const N: usize = 3;
+}
+
+fn foo<F: Foo<N=3>>() {}
+fn main() {}

src/tools/clippy/clippy_utils/src/ast_utils.rs

@@ -645,12 +645,13 @@ pub fn eq_generic_bound(l: &GenericBound, r: &GenericBound) -> bool {
     }
 }
 
-pub fn eq_assoc_constraint(l: &AssocTyConstraint, r: &AssocTyConstraint) -> bool {
-    use AssocTyConstraintKind::*;
+pub fn eq_assoc_constraint(l: &AssocConstraint, r: &AssocConstraint) -> bool {
+    use AssocConstraintKind::*;
     eq_id(l.ident, r.ident)
         && match (&l.kind, &r.kind) {
             (Equality { ty: l }, Equality { ty: r }) => eq_ty(l, r),
             (Bound { bounds: l }, Bound { bounds: r }) => over(l, r, eq_generic_bound),
+            (ConstEquality { c: l }, ConstEquality { c: r }) => eq_anon_const(l, r),
             _ => false,
         }
 }

src/tools/rustfmt/src/types.rs

@@ -141,7 +141,7 @@ pub(crate) enum SegmentParam<'a> {
     Const(&'a ast::AnonConst),
     LifeTime(&'a ast::Lifetime),
     Type(&'a ast::Ty),
-    Binding(&'a ast::AssocTyConstraint),
+    Binding(&'a ast::AssocConstraint),
 }
 
 impl<'a> SegmentParam<'a> {
@@ -176,9 +176,9 @@ impl<'a> Rewrite for SegmentParam<'a> {
     }
 }
 
-impl Rewrite for ast::AssocTyConstraint {
+impl Rewrite for ast::AssocConstraint {
     fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
-        use ast::AssocTyConstraintKind::{Bound, Equality};
+        use ast::AssocConstraintKind::{Bound, Equality, ConstEquality};
 
         let mut result = String::with_capacity(128);
         result.push_str(rewrite_ident(context, self.ident));
@@ -192,8 +192,8 @@ impl Rewrite for ast::AssocTyConstraint {
 
         let infix = match (&self.kind, context.config.type_punctuation_density()) {
             (Bound { .. }, _) => ": ",
-            (Equality { .. }, TypeDensity::Wide) => " = ",
-            (Equality { .. }, TypeDensity::Compressed) => "=",
+            (ConstEquality { .. } | Equality { .. }, TypeDensity::Wide) => " = ",
+            (ConstEquality { .. } | Equality { .. }, TypeDensity::Compressed) => "=",
         };
         result.push_str(infix);
 
@@ -206,11 +206,12 @@ impl Rewrite for ast::AssocTyConstraint {
     }
 }
 
-impl Rewrite for ast::AssocTyConstraintKind {
+impl Rewrite for ast::AssocConstraintKind {
     fn rewrite(&self, context: &RewriteContext<'_>, shape: Shape) -> Option<String> {
         match self {
-            ast::AssocTyConstraintKind::Equality { ty } => ty.rewrite(context, shape),
-            ast::AssocTyConstraintKind::Bound { bounds } => bounds.rewrite(context, shape),
+            ast::AssocConstraintKind::Equality { ty } => ty.rewrite(context, shape),
+            ast::AssocConstraintKind::ConstEquality { c } => c.rewrite(context, shape),
+            ast::AssocConstraintKind::Bound { bounds } => bounds.rewrite(context, shape),
         }
     }
 }