1 files changed, 11 insertions, 0 deletions
diff --git a/source/slang/expr-defs.h b/source/slang/expr-defs.h
index fb29f64de..bd4ba5038 100644
--- a/source/slang/expr-defs.h
+++ b/source/slang/expr-defs.h
@@ -193,3 +193,14 @@ RAW(
     DeclRef<VarDeclBase> declRef;
 )
 END_SYNTAX_CLASS()
+
+    /// A type expression of the form `__TaggedUnion(A, ...)`.
+    ///
+    /// An expression of this form will resolve to a `TaggedUnionType`
+    /// when checked.
+    ///
+SYNTAX_CLASS(TaggedUnionTypeExpr, Expr)
+RAW(
+    List<TypeExp> caseTypes;
+)
+END_SYNTAX_CLASS()
+\ No newline at end of file