'Explicit specialization' experiments with extensions (#2099)

* #include an absolute path didn't work - because paths were taken to always be relative.

* Explicit specialization with multiple parameters.

* Fix tabs.

* Small improvements in test comments.

1 files changed, 38 insertions, 0 deletions

diff --git a/tests/experiments/generic/explicit-specialization.slang b/tests/experiments/generic/explicit-specialization.slang
new file mode 100644
index 000000000..0eaa1da27
--- /dev/null
+++ b/tests/experiments/generic/explicit-specialization.slang
@@ -0,0 +1,38 @@
+//DISABLE_TEST:SIMPLE:-target hlsl -entry computeMain -profile cs_6_2
+
+/* Slang doesn't have explicit template specialization. 
+Here's an attempt to use the extension mechanism. 
+
+This doesn't work and produces 9 errors of the form
+>  error 30052: invalid swizzle pattern 'rotateLeft' on type 'uint'
+> let v = tid.rotateLeft();
+
+Presumably for each letter of 'rotateLeft' after r, thinking it's a swizzle?
+*/
+
+RWStructuredBuffer<int> outputBuffer;
+
+interface IRotatable 
+{
+    This rotateLeft();
+};
+
+extension int : IRotatable
+{
+    This rotateLeft() { const uint u = this; return This((u << 1) | (u >> 31)); }
+};
+
+extension uint : IRotatable
+{
+    This rotateLeft() { let u = this; return This((u << 1) | (u >> 31)); }
+};
+
+[numthreads(4, 1, 1)]
+void computeMain(uint3 dispatchThreadID : SV_DispatchThreadID)
+{
+    uint tid = dispatchThreadID.x;
+
+    uint v = tid.rotateLeft();
+   
+    outputBuffer[tid] = v;
+}