[SYCL] Add size_type, to accessor and local_accessor classes.

sycl/include/sycl/accessor.hpp

@@ -1253,6 +1253,7 @@ class __SYCL_EBO __SYCL_SPECIAL_CLASS __SYCL_TYPE(accessor) accessor :
   using const_reverse_iterator = std::reverse_iterator<const_iterator>;
   using difference_type =
       typename std::iterator_traits<iterator>::difference_type;
+  using size_type = size_t;
 
   // The list of accessor constructors with their arguments
   // -------+---------+-------+----+-----+--------------
@@ -1980,11 +1981,11 @@ class __SYCL_EBO __SYCL_SPECIAL_CLASS __SYCL_TYPE(accessor) accessor :
 
   __SYCL2020_DEPRECATED("get_count() is deprecated, please use size() instead")
   size_t get_count() const { return size(); }
-  size_t size() const noexcept { return getAccessRange().size(); }
+  size_type size() const noexcept { return getAccessRange().size(); }
 
-  size_t byte_size() const noexcept { return size() * sizeof(DataT); }
+  size_type byte_size() const noexcept { return size() * sizeof(DataT); }
 
-  size_t max_size() const noexcept {
+  size_type max_size() const noexcept {
     return empty() ? 0 : (std::numeric_limits<difference_type>::max)();
   }
 
@@ -2733,15 +2734,16 @@ class __SYCL_EBO __SYCL_SPECIAL_CLASS __SYCL_TYPE(local_accessor) local_accessor
   using const_reverse_iterator = std::reverse_iterator<const_iterator>;
   using difference_type =
       typename std::iterator_traits<iterator>::difference_type;
+  using size_type = size_t;
 
   template <access::decorated IsDecorated>
   using accessor_ptr = local_ptr<value_type, IsDecorated>;
 
   void swap(local_accessor &other) { std::swap(this->impl, other.impl); }
 
-  size_t byte_size() const noexcept { return this->size() * sizeof(DataT); }
+  size_type byte_size() const noexcept { return this->size() * sizeof(DataT); }
 
-  size_t max_size() const noexcept {
+  size_type max_size() const noexcept {
     return empty() ? 0 : (std::numeric_limits<difference_type>::max)();
   }
 

sycl/test/basic_tests/accessor/accessor_size_type.cpp

@@ -0,0 +1,15 @@
+// RUN: %clangxx -fsycl -fsycl-targets=%sycl_triple %s -o %t.out
+// RUN: %t.out
+
+#include <sycl/sycl.hpp>
+#include <type_traits>
+
+int main() {
+  using accessor_size_type = sycl::accessor<int, 3>::size_type;
+  using local_accessor_size_type = sycl::local_accessor<int, 3>::size_type;
+  using host_accessor_size_type = sycl::host_accessor<int, 3>::size_type;
+
+  static_assert(std::is_same_v<accessor_size_type, size_t>);
+  static_assert(std::is_same_v<local_accessor_size_type, size_t>);
+  static_assert(std::is_same_v<host_accessor_size_type, size_t>);
+}