Add memory_resource reference comparison.

Add operator bool in resource view.
Disallow construction of resource_view from integer (0).
Add context to as_kind.

Signed-off-by: Michał Zientkiewicz <[email protected]>

include/cuda/memory_resource

@@ -75,6 +75,9 @@ struct any_context{};
 
 namespace detail {
 
+template <typename...>
+struct __type_pack {};
+
 namespace __fallback_typeid {
 
 template <class _Tp>
@@ -222,21 +225,23 @@ public:
   /*!
    * \brief Tries to cast the resource to a resource of given kind
    */
-  template <typename _Kind>
+  template <typename _Kind, typename _Context = any_context>
   memory_resource<_Kind> *as_kind() noexcept {
+    using __tag = detail::__type_pack<_Kind, _Context>;
     return static_cast<memory_resource<_Kind> *>(
-          __do_as_kind(detail::__fallback_typeid::__get_typeid<_Kind*>(),
-                       detail::__fallback_typeid::__get_fallback_typeid<_Kind*>()));
+          __do_as_kind(detail::__fallback_typeid::__get_typeid<__tag>(),
+                       detail::__fallback_typeid::__get_fallback_typeid<__tag>()));
   }
 
   /*!
    * \brief Tries to cast the resource to a resource of given kind
    */
-  template <typename _Kind>
-  const memory_resource<_Kind> *as_kind() const noexcept {
-    return static_cast<const memory_resource<_Kind> *>(
-          __do_as_kind(detail::__fallback_typeid::__get_typeid<_Kind*>(),
-                       detail::__fallback_typeid::__get_fallback_typeid<_Kind*>()));
+  template <typename _Kind, typename _Context = any_context>
+  const memory_resource<_Kind, _Context> *as_kind() const noexcept {
+    using __tag = detail::__type_pack<_Kind, _Context>;
+    return static_cast<const memory_resource<_Kind, _Context> *>(
+          __do_as_kind(detail::__fallback_typeid::__get_typeid<__tag>(),
+                       detail::__fallback_typeid::__get_fallback_typeid<__tag>()));
   }
 
 protected:
@@ -252,7 +257,7 @@ protected:
   template <typename _ResourcePointer, typename... _Properties>
   friend class cuda::basic_resource_view;
 
-  virtual void *__do_as_kind(const ::std::type_info *__kind_type_id, const void *__kind_type_fallback_id) const noexcept = 0;
+  virtual void *__do_as_kind(const ::std::type_info *__tag_type_id, const void *__tag_type_fallback_id) const noexcept = 0;
 };
 
 class stream_ordered_memory_resource_base : public virtual memory_resource_base {
@@ -469,21 +474,27 @@ private:
     return this == &__other;
   }
 
-  void *__do_as_kind(const ::std::type_info *__kind_type_id, const void *__kind_type_fallback_id) const noexcept final {
-    return detail::__fallback_typeid::__is_type<memory_kind*>(__kind_type_id, __kind_type_fallback_id)
+  void *__do_as_kind(const ::std::type_info *__tag_type_id, const void *__tag_type_fallback_id) const noexcept final {
+    using __tag = detail::__type_pack<memory_kind, context>;
+    return detail::__fallback_typeid::__is_type<__tag>(__tag_type_id, __tag_type_fallback_id)
               ? const_cast<memory_resource*>(this) : nullptr;
   }
 
   bool is_equal_base(const detail::memory_resource_base &__other) const noexcept final {
-    if (auto *__other_res = __other.as_kind<memory_kind>()) {
+    if (auto *__other_res = __other.as_kind<memory_kind, context>()) {
       return do_is_equal(*__other_res);
     } else {
       return false;
     }
   }
-
 };
 
+template <typename _Kind, typename _Context>
+inline _LIBCUDACXX_INLINE_VISIBILITY
+bool operator==(const memory_resource<_Kind, _Context> &__a, const memory_resource<_Kind, _Context> &__b) {
+  return __a.is_equal(__b);
+}
+
 /*!
  * \brief Abstract interface for CUDA stream-ordered memory allocation.
  *
@@ -793,6 +804,8 @@ public:
 
     basic_resource_view() = default;
 
+    basic_resource_view(int) = delete;
+
     basic_resource_view(std::nullptr_t) {}
 
     /*!
@@ -832,7 +845,6 @@ public:
      */
     _ResourcePointer operator->() const noexcept { return __pointer; }
 
-
     template <typename _Ptr2, typename... _Props2>
     bool operator==(const cuda::basic_resource_view<_Ptr2, _Props2...> &__v2) const noexcept {
       using __view1_t = basic_resource_view;
@@ -847,6 +859,12 @@ public:
       return !(*this == __v2);
     }
 
+    /*!
+     * \brief Returns true if the underlying pointer is not null.
+     */
+    constexpr explicit operator bool() const noexcept {
+      return !!__pointer;
+    }
 
 private:
     template <typename, typename...>