Add `none` literal that is convertible to `Optional`. (#2356)

* Add `none` literal that is convertible to `Optional`.

* Fix cpu code gen.

* Include vk and cpu test for is-as operator test.

* Inline comparison operators.

Co-authored-by: Yong He <yhe@nvidia.com>

1 files changed, 34 insertions, 0 deletions

diff --git a/source/slang/core.meta.slang b/source/slang/core.meta.slang
index 616511b01..d912fe8ce 100644
--- a/source/slang/core.meta.slang
+++ b/source/slang/core.meta.slang
@@ -349,6 +349,12 @@ struct NullPtr
 {
 };
 
+__magic_type(NoneType)
+__intrinsic_type($(kIROp_VoidType))
+struct __none_t
+{
+};
+
 __generic<T>
 __magic_type(PtrType)
 __intrinsic_type($(kIROp_PtrType))
@@ -472,8 +478,36 @@ struct Optional
         __intrinsic_op($(kIROp_GetOptionalValue))
         get;
     }
+
+    __implicit_conversion($(kConversionCost_ValToOptional))
+    __intrinsic_op($(kIROp_MakeOptionalValue))
+    __init(T val);
 };
 
+__generic<T>
+[__unsafeForceInlineEarly]
+bool operator==(Optional<T> val, __none_t noneVal)
+{
+    return !val.hasValue;
+}
+__generic<T>
+[__unsafeForceInlineEarly]
+bool operator!=(Optional<T> val, __none_t noneVal)
+{
+    return val.hasValue;
+}
+__generic<T>
+[__unsafeForceInlineEarly]
+bool operator==(__none_t noneVal, Optional<T> val)
+{
+    return !val.hasValue;
+}
+__generic<T>
+[__unsafeForceInlineEarly]
+bool operator!=(__none_t noneVal, Optional<T> val)
+{
+    return val.hasValue;
+}
 
 __magic_type(StringType)
 __intrinsic_type($(kIROp_StringType))