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>

2 files changed, 55 insertions, 0 deletions

diff --git a/tests/language-feature/types/optional.slang b/tests/language-feature/types/optional.slang
new file mode 100644
index 000000000..ae1711cd7
--- /dev/null
+++ b/tests/language-feature/types/optional.slang
@@ -0,0 +1,53 @@
+// optional.slang
+
+// Test that `Optional` construction and conversion works.
+
+//TEST(compute):COMPARE_COMPUTE_EX:-slang -compute
+//TEST(compute):COMPARE_COMPUTE_EX:-slang -vk -compute
+//TEST(compute):COMPARE_COMPUTE_EX:-slang -cpu -compute
+
+//TEST_INPUT:ubuffer(data=[0 0 0 0], stride=4):out,name=outputBuffer
+RWStructuredBuffer<int> outputBuffer;
+
+[anyValueSize(8)]
+interface IFoo
+{
+    int method();
+}
+
+//TEST_INPUT: type_conformance Impl1:IFoo = 0
+struct Impl1 : IFoo
+{
+    int data;
+    int method() { return data; }
+}
+
+Optional<Impl1> getVal(bool shouldHaveVal)
+{
+    if (shouldHaveVal)
+    {
+        Impl1 val;
+        val.data = 1;
+        return val;
+    }
+    return none;
+}
+
+[numthreads(1, 1, 1)]
+void computeMain(uint3 dispatchThreadID: SV_DispatchThreadID)
+{
+    let v1 = getVal(true);
+    let v2 = getVal(false);
+    int result = 0;
+    if (v1.hasValue)
+        result += v1.value.data;
+    if (v2.hasValue)
+        result += v2.value.data;
+    outputBuffer[0] = result;
+    if (v1 != none)
+        result += v1.value.data;
+    if (!(v2 == none))
+        result += v2.value.data;
+    outputBuffer[1] = result;
+
+}
diff --git a/tests/language-feature/types/optional.slang.expected.txt b/tests/language-feature/types/optional.slang.expected.txt
new file mode 100644
index 000000000..1191247b6
--- /dev/null
+++ b/tests/language-feature/types/optional.slang.expected.txt
@@ -0,0 +1,2 @@
+1
+2