Auto merge of #619 - detrumi:opaque-types-without-bounds, r=jackh726

Parse opaque types without bounds

Author: bors

chalk-parse/src/parser.lalrpop

@@ -251,13 +251,13 @@ AssocTyDefn: AssocTyDefn = {
 };
 
 OpaqueTyDefn: OpaqueTyDefn = {
-    "opaque" "type" <name:Id> <p:Angle<VariableKind>> ":" <b:Plus<QuantifiedInlineBound>>
+    "opaque" "type" <name:Id> <p:Angle<VariableKind>> <b:(":" <Plus<QuantifiedInlineBound>>)?>
         <w:QuantifiedWhereClauses> "=" <ty:Ty> ";" => {
         OpaqueTyDefn {
             ty,
             variable_kinds: p,
             name,
-            bounds: b,
+            bounds: b.unwrap_or(vec![]),
             where_clauses: w,
         }
     }

tests/display/const_.rs

@@ -40,7 +40,7 @@ fn test_basic_const_values_in_opaque_ty_values() {
     reparse_test!(
         program {
             struct Foo<const N> { }
-            opaque type Zed: = Foo<0>;
+            opaque type Zed = Foo<0>;
         }
     );
 }

tests/display/fn_.rs

@@ -41,7 +41,7 @@ fn test_opaque_ty_with_fn_def() {
     // Test printing opaque types in function definitions
     reparse_test!(
         program {
-            opaque type Bar: = ();
+            opaque type Bar = ();
             fn gives_bar() -> Bar;
             fn receives_bar(param: Bar) -> ();
         }

tests/display/opaque_ty.rs

@@ -23,7 +23,7 @@ fn opaque_ty_no_bounds() {
     // Test printing opaque types without any bounds
     reparse_test!(
         program {
-            opaque type Foo: = ();
+            opaque type Foo = ();
         }
     );
 }