Tuple swizzling, concat, comparison and `countof`. (#4856)

* Tuple swizzling and element access.

* Update proposal status.

* Cleanup.

* Fix merrge error.

* Address review.

1 files changed, 18 insertions, 1 deletions

diff --git a/source/slang/slang-ast-builder.cpp b/source/slang/slang-ast-builder.cpp
index 3a2b2933d..a13e13851 100644
--- a/source/slang/slang-ast-builder.cpp
+++ b/source/slang/slang-ast-builder.cpp
@@ -572,9 +572,26 @@ Type* ASTBuilder::getExpandType(Type* pattern, ArrayView<Type*> capturedPacks)
     return getOrCreate<ExpandType>(pattern, capturedPacks);
 }
 
+void flattenTypeList(ShortList<Type*>& flattenedList, Type* type)
+{
+    if (auto typePack = as<ConcreteTypePack>(type))
+    {
+        for (Index i = 0; i < typePack->getTypeCount(); i++)
+            flattenTypeList(flattenedList, typePack->getElementType(i));
+    }
+    else
+    {
+        flattenedList.add(type);
+    }
+}
+
 ConcreteTypePack* ASTBuilder::getTypePack(ArrayView<Type*> types)
 {
-    return getOrCreate<ConcreteTypePack>(types);
+    // Flatten all type packs in the type list.
+    ShortList<Type*> flattenedTypes;
+    for (auto type : types)
+        flattenTypeList(flattenedTypes, type);
+    return getOrCreate<ConcreteTypePack>(flattenedTypes.getArrayView().arrayView);
 }
 
 TypeEqualityWitness* ASTBuilder::getTypeEqualityWitness(