Allow `Optional`, `Tuple` and `bool` to be used in varying input/output. (#5889)

* Allow `Optional` and `Tuple` to be used in varying input/output.

* Fix.

* format code

* Fix.

* Fix test.

* Fix.

* enhance test.

* Fix.

* format code

---------

Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com>

1 files changed, 9 insertions, 1 deletions

diff --git a/source/slang/slang-type-layout.cpp b/source/slang/slang-type-layout.cpp
index b54f813dd..17f1ae677 100644
--- a/source/slang/slang-type-layout.cpp
+++ b/source/slang/slang-type-layout.cpp
@@ -4785,10 +4785,18 @@ static TypeLayoutResult _createTypeLayout(TypeLayoutContext& context, Type* type
             type,
             rules);
     }
+    else if (auto optionalType = as<OptionalType>(type))
+    {
+        // OptionalType should be laid out the same way as Tuple<T, bool>.
+        Array<Type*, 2> types =
+            makeArray(optionalType->getValueType(), context.astBuilder->getBoolType());
+        auto tupleType = context.astBuilder->getTupleType(types.getView());
+        return _createTypeLayout(context, tupleType);
+    }
     else if (auto tupleType = as<TupleType>(type))
     {
         // A `Tuple` type is laid out exactly the same way as a `struct` type,
-        // except that we want have a declref to the field.
+        // except that we won't have a declref to the field.
 
         StructTypeLayoutBuilder typeLayoutBuilder;
         StructTypeLayoutBuilder pendingDataTypeLayoutBuilder;