[SYCL] annotated_ptr API fixes part 2 (#10928)

Remove `operator=(const T*)`. This one isn't deprecated because it was
broken (trying to return temp as reference) and therefore can't have
users.

Also add missing `const` for copy constructor.

Author: rolandschulz

sycl/doc/extensions/experimental/sycl_ext_oneapi_annotated_ptr.asciidoc

@@ -288,7 +288,6 @@ class annotated_ptr {
 
     T* get() const noexcept;
 
-    annotated_ptr& operator=(T*) noexcept;
     annotated_ptr& operator=(const annotated_ptr&) noexcept = default;
 
     annotated_ptr& operator++() noexcept;
@@ -447,15 +446,6 @@ T* get() const noexcept;
 Returns the underlying raw pointer. The raw pointer will not retain the
 annotations.
 
-// --- ROW BREAK ---
-a|
-[source,c++]
-----
-annotated_ptr& operator=(T*) noexcept;
-----
-|
-Allows assignment from a pointer to type `T`.
-
 // --- ROW BREAK ---
 a|
 [source,c++]

sycl/include/sycl/ext/oneapi/experimental/annotated_ptr/annotated_ptr.hpp

@@ -238,7 +238,7 @@ __SYCL_TYPE(annotated_ptr) annotated_ptr<T, detail::properties_t<Props...>> {
 
   annotated_ptr() noexcept = default;
   annotated_ptr(const annotated_ptr &) = default;
-  annotated_ptr &operator=(annotated_ptr &) = default;
+  annotated_ptr &operator=(const annotated_ptr &) = default;
 
   annotated_ptr(T *Ptr, const property_list_t & = properties{}) noexcept
       : m_Ptr(global_pointer_t(Ptr)) {}
@@ -321,10 +321,6 @@ __SYCL_TYPE(annotated_ptr) annotated_ptr<T, detail::properties_t<Props...>> {
 
   T *get() const noexcept { return m_Ptr; }
 
-  annotated_ptr &operator=(T *) noexcept {
-    return annotated_ptr<T, property_list_t>(m_Ptr);
-  }
-
   annotated_ptr &operator++() noexcept {
     m_Ptr += 1;
     return *this;

sycl/test/extensions/annotated_arg/annotated_ptr.cpp

@@ -110,6 +110,9 @@ void TestVectorAddWithAnnotatedMMHosts() {
   // annotated_ptr<int, decltype(properties{dwidth<32>})> arg24(tmp21,
   // properties{dwidth<32>});   // ERR
 
+  // Implicit conversion
+  a1 = raw;
+
   // Property merge
   auto arg31 = annotated_ptr_t3(raw, buffer_location<0>, awidth<32>);     // OK
   auto arg32 = annotated_ptr(arg31, properties{dwidth<32>});              // OK