From c521a847450033461fa6257aba0b2202bb1d62af Mon Sep 17 00:00:00 2001
From: Peter Colberg <peter.colberg@intel.com>
Date: Thu, 24 Mar 2022 19:34:39 -0400
Subject: [PATCH] [SYCL][FPGA] prepare future implementation of experimental
 pipe properties

Add a template parameter to pass compile-time constant properties to
sycl::ext::intel::experimental::pipe, and redeclare pipe implementation
as a specialization when the properties list is empty; otherwise, when
the properties list is non-empty, throw a descriptive compiler error.

The unnamed template parameter allows implementation of the case where
the properties list is non-empty in a downstream, FPGA-specific header,
before finalizing pipe properties for inclusion into this header.

See draft specification in https://github.com/intel/llvm/pull/5838
---
 .../sycl/ext/intel/experimental/pipes.hpp        | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/sycl/include/sycl/ext/intel/experimental/pipes.hpp b/sycl/include/sycl/ext/intel/experimental/pipes.hpp
index 46494884c29ba..442cea8c93062 100644
--- a/sycl/include/sycl/ext/intel/experimental/pipes.hpp
+++ b/sycl/include/sycl/ext/intel/experimental/pipes.hpp
@@ -12,6 +12,8 @@
 #include <CL/__spirv/spirv_ops.hpp>
 #include <CL/__spirv/spirv_types.hpp>
 #include <CL/sycl/stl.hpp>
+#include <sycl/ext/oneapi/properties/properties.hpp>
+#include <type_traits>
 
 __SYCL_INLINE_NAMESPACE(cl) {
 namespace sycl {
@@ -19,7 +21,19 @@ namespace ext {
 namespace intel {
 namespace experimental {
 
-template <class _name, class _dataT, int32_t _min_capacity = 0> class pipe {
+template <class _name, class _dataT, int32_t _min_capacity = 0,
+          class _propertiesT = decltype(oneapi::experimental::properties{}),
+          class = void>
+class pipe {
+  static_assert(std::is_same_v<_propertiesT,
+                               decltype(oneapi::experimental::properties{})>,
+                "experimental pipe properties are not yet implemented");
+};
+
+template <class _name, class _dataT, int32_t _min_capacity, class _propertiesT>
+class pipe<_name, _dataT, _min_capacity, _propertiesT,
+           std::enable_if_t<std::is_same_v<
+               _propertiesT, decltype(oneapi::experimental::properties{})>>> {
 public:
   // Non-blocking pipes
   // Reading from pipe is lowered to SPIR-V instruction OpReadPipe via SPIR-V