[SYCL] Add multi_ptr deduction guide

Signed-off-by: Roland Schulz <[email protected]>

Author: rolandschulz

sycl/include/CL/sycl/multi_ptr.hpp

@@ -503,6 +503,23 @@ class multi_ptr<const void, Space> {
   pointer_t m_Pointer;
 };
 
+#ifdef __cpp_deduction_guides
+template <int dimensions, access::mode Mode, access::placeholder isPlaceholder,
+          class T>
+multi_ptr(
+    accessor<T, dimensions, Mode, access::target::global_buffer, isPlaceholder>)
+    ->multi_ptr<T, access::address_space::global_space>;
+template <int dimensions, access::mode Mode, access::placeholder isPlaceholder,
+          class T>
+multi_ptr(accessor<T, dimensions, Mode, access::target::constant_buffer,
+                   isPlaceholder>)
+    ->multi_ptr<T, access::address_space::constant_space>;
+template <int dimensions, access::mode Mode, access::placeholder isPlaceholder,
+          class T>
+multi_ptr(accessor<T, dimensions, Mode, access::target::local, isPlaceholder>)
+    ->multi_ptr<T, access::address_space::local_space>;
+#endif
+
 template <typename ElementType, access::address_space Space>
 multi_ptr<ElementType, Space>
 make_ptr(typename multi_ptr<ElementType, Space>::pointer_t pointer) {

sycl/test/multi_ptr/ctad.cpp

@@ -0,0 +1,30 @@
+// RUN: %clangxx -std=c++17 -fsyntax-only -Xclang -verify %s
+// expected-no-diagnostics
+//==--------------- ctad.cpp - SYCL multi_ptr CTAD test --------------------==//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+#include <CL/sycl.hpp>
+
+namespace sycl = cl::sycl;
+
+int main() {
+  using sycl::access::address_space;
+  using sycl::access::mode;
+  using sycl::access::target;
+  using globlAcc = sycl::accessor<int, 1, mode::read, target::global_buffer>;
+  using constAcc = sycl::accessor<int, 1, mode::read, target::constant_buffer>;
+  using localAcc = sycl::accessor<int, 1, mode::read, target::local>;
+  using globlCTAD = decltype(sycl::multi_ptr(std::declval<globlAcc>()));
+  using constCTAD = decltype(sycl::multi_ptr(std::declval<constAcc>()));
+  using localCTAD = decltype(sycl::multi_ptr(std::declval<localAcc>()));
+  using globlMPtr = sycl::multi_ptr<int, address_space::global_space>;
+  using constMPtr = sycl::multi_ptr<int, address_space::constant_space>;
+  using localMPtr = sycl::multi_ptr<int, address_space::local_space>;
+  static_assert(std::is_same_v<globlCTAD, globlMPtr>);
+  static_assert(std::is_same_v<constCTAD, constMPtr>);
+  static_assert(std::is_same_v<localCTAD, localMPtr>);
+}