Merge #900

900: Add new trait ast::TypeAscriptionOwner r=vipentti a=vipentti

This trait should be implemented for nodes which have an ascribed type,
e.g. thing : Type. Such as let, const, static, param, named struct fields.

In addition, we update some places where previously we used node + node.type_ref() with `TypeAscriptionOwner` in the trait bounds.

Co-authored-by: Ville Penttinen <[email protected]>

1 files changed, 6 insertions, 0 deletions

diff --git a/crates/ra_syntax/src/ast.rs b/crates/ra_syntax/src/ast.rs
index 56fb7c20c..81c709bfb 100644
--- a/crates/ra_syntax/src/ast.rs
+++ b/crates/ra_syntax/src/ast.rs
@@ -31,6 +31,12 @@ pub trait AstToken: AstNode {
     }
 }
 
+pub trait TypeAscriptionOwner: AstNode {
+    fn ascribed_type(&self) -> Option<&TypeRef> {
+        child_opt(self)
+    }
+}
+
 pub trait NameOwner: AstNode {
     fn name(&self) -> Option<&Name> {
         child_opt(self)