From feba2435b10de6e8c259356d21451de4276ee5b5 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Le=C3=B3n=20Orell=20Valerian=20Liehr?= <me@fmease.dev>
Date: Tue, 5 May 2026 09:23:19 +0200
Subject: [PATCH 1/2] Fix grammar rules containing bounds

---
 src/items/type-aliases.md | 2 +-
 src/paths.md              | 2 +-
 src/types/impl-trait.md   | 4 ++--
 src/types/trait-object.md | 4 ++--
 4 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/items/type-aliases.md b/src/items/type-aliases.md
index c21981eb85..9a9dec0e26 100644
--- a/src/items/type-aliases.md
+++ b/src/items/type-aliases.md
@@ -4,7 +4,7 @@ r[items.type]
 r[items.type.syntax]
 ```grammar,items
 TypeAlias ->
-    `type` IDENTIFIER GenericParams? ( `:` Bounds )?
+    `type` IDENTIFIER GenericParams? ( `:` Bounds? )?
         WhereClause?
         ( `=` Type WhereClause?)? `;`
 ```
diff --git a/src/paths.md b/src/paths.md
index cb36f3af20..2a141f2846 100644
--- a/src/paths.md
+++ b/src/paths.md
@@ -68,7 +68,7 @@ GenericArgsBinding ->
     IDENTIFIER GenericArgs? `=` Type
 
 GenericArgsBounds ->
-    IDENTIFIER GenericArgs? `:` Bounds
+    IDENTIFIER GenericArgs? `:` Bounds?
 ```
 
 r[paths.expr.intro]
diff --git a/src/types/impl-trait.md b/src/types/impl-trait.md
index 68bee6c025..1a6ad5639c 100644
--- a/src/types/impl-trait.md
+++ b/src/types/impl-trait.md
@@ -3,9 +3,9 @@ r[type.impl-trait]
 
 r[type.impl-trait.syntax]
 ```grammar,types
-ImplTraitType -> `impl` Bounds
+ImplTraitType -> `impl` Bounds?
 
-ImplTraitTypeOneBound -> `impl` TraitBound
+ImplTraitTypeOneBound -> `impl` TraitBound?
 ```
 
 r[type.impl-trait.intro]
diff --git a/src/types/trait-object.md b/src/types/trait-object.md
index 7b07b6a05c..fa33c106bc 100644
--- a/src/types/trait-object.md
+++ b/src/types/trait-object.md
@@ -3,9 +3,9 @@ r[type.trait-object]
 
 r[type.trait-object.syntax]
 ```grammar,types
-TraitObjectType -> `dyn`? Bounds
+TraitObjectType -> Bounds | `dyn` Bounds?
 
-TraitObjectTypeOneBound -> `dyn`? TraitBound
+TraitObjectTypeOneBound -> TraitBound | `dyn` TraitBound?
 ```
 
 r[type.trait-object.intro]

From e8c2309e7ad12d1321718f2f9f4a5307c618f87f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Le=C3=B3n=20Orell=20Valerian=20Liehr?= <me@fmease.dev>
Date: Tue, 5 May 2026 10:04:18 +0200
Subject: [PATCH 2/2] Revise section about `dyn` in Rust 2015

---
 src/types/trait-object.md | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/types/trait-object.md b/src/types/trait-object.md
index fa33c106bc..b66c2536c3 100644
--- a/src/types/trait-object.md
+++ b/src/types/trait-object.md
@@ -37,7 +37,9 @@ r[type.trait-object.syntax-edition2021]
 
 r[type.trait-object.syntax-edition2018]
 > [!EDITION-2018]
-> In the 2015 edition, if the first bound of the trait object is a path that starts with `::`, then the `dyn` will be treated as a part of the path. The first path can be put in parenthesis to get around this. As such, if you want a trait object with the trait `::your_module::Trait`, you should write it as `dyn (::your_module::Trait)`.
+> In the 2015 edition, `dyn` must be followed by [PathIdentSegment][grammar-PathIdentSegment], [LIFETIME_OR_LABEL][grammar-LIFETIME_OR_LABEL], `for`, `(` or `?` to be interpreted as the start of a trait object type. Otherwise, it will be interpreted as a regular identifier.
+>
+> Most notably, `dyn`, `dyn::T` and `dyn<T>` will all be treated as type paths. The first path can be put in parenthesis to get around this. As such, if you want a trait object with the trait `::module::Trait`, you should write it as `dyn (::module::Trait)`.
 >
 > Beginning in the 2018 edition, `dyn` is a true keyword and is not allowed in paths, so the parentheses are not necessary.