Make properties::get_property static for compile-time properties

Author: aelovikov-intel

sycl/include/sycl/ext/oneapi/properties/properties.hpp

@@ -220,7 +220,32 @@ class __SYCL_EBO
                              properties>;
   }
 
-  template <typename property_key_t> constexpr auto get_property() {
+  // Two methods below do the following (pseudocode):
+  //
+  // template <property_key_t>
+  // using ret_t = decltype(this->get_property(key_tag<property_key_t>{}));
+  // static constexpr auto get_property() requires(is_empty_v<ret_t>) {
+  //   return ret_t{};
+  // }
+  // constexpr auto get_property() requires(!is_empty_v<ret_t>) {
+  //   return get_property(key_tag<property_key_t>{});
+  // }
+  template <typename property_key_t>
+  static constexpr auto get_property() -> std::enable_if_t<
+      std::is_empty_v<decltype(std::declval<properties>().get_property(
+          detail::property_key_tag<property_key_t>{}))>,
+      decltype(std::declval<properties>().get_property(
+          detail::property_key_tag<property_key_t>{}))> {
+    return decltype(std::declval<properties>().get_property(
+        detail::property_key_tag<property_key_t>{})){};
+  }
+
+  template <typename property_key_t>
+  constexpr auto get_property() const -> std::enable_if_t<
+      !std::is_empty_v<decltype(std::declval<properties>().get_property(
+          detail::property_key_tag<property_key_t>{}))>,
+      decltype(std::declval<properties>().get_property(
+          detail::property_key_tag<property_key_t>{}))> {
     return get_property(detail::property_key_tag<property_key_t>{});
   }
 

sycl/test/extensions/properties/new_properties.cpp

@@ -159,6 +159,18 @@ void test() {
 }
 } // namespace test_compile_prop_in_runtime_list
 
+namespace test_static_get_property {
+  struct ct_prop : named_property_base<ct_prop> {};
+  struct rt_prop : named_property_base<rt_prop> {
+    int x;
+  };
+  void test() {
+    properties pl{ct_prop{}, rt_prop{}};
+    constexpr auto c = decltype(pl)::get_property<ct_prop>();
+    auto r = pl.get_property<rt_prop>();
+  }
+}
+
 int main() {
   test::test();
   bench::test(std::make_integer_sequence<int, 67>{});