Use the nullptr literal instead of std::nullptr_t parameters in

`thrust::pointer` and `thrust::device_ptr` to silence spurious "set but not
used" warnings from old GCC versions.

Author: brycelelbach

thrust/detail/pointer.h

@@ -14,7 +14,7 @@
  *  limitations under the License.
  */
 
-/*! \file 
+/*! \file
  *  \brief A pointer to a variable which resides in memory associated with a
  *  system.
  */
@@ -235,19 +235,19 @@ operator<<(std::basic_ostream<charT, traits> &os,
 // `std::unique_ptr`.
 template <typename Element, typename Tag, typename Reference, typename Derived>
 __host__ __device__
-bool operator==(std::nullptr_t np, pointer<Element, Tag, Reference, Derived> p);
+bool operator==(std::nullptr_t, pointer<Element, Tag, Reference, Derived> p);
 
 template <typename Element, typename Tag, typename Reference, typename Derived>
 __host__ __device__
-bool operator==(pointer<Element, Tag, Reference, Derived> p, std::nullptr_t np);
+bool operator==(pointer<Element, Tag, Reference, Derived> p, std::nullptr_t);
 
 template <typename Element, typename Tag, typename Reference, typename Derived>
 __host__ __device__
-bool operator!=(std::nullptr_t np, pointer<Element, Tag, Reference, Derived> p);
+bool operator!=(std::nullptr_t, pointer<Element, Tag, Reference, Derived> p);
 
 template <typename Element, typename Tag, typename Reference, typename Derived>
 __host__ __device__
-bool operator!=(pointer<Element, Tag, Reference, Derived> p, std::nullptr_t np);
+bool operator!=(pointer<Element, Tag, Reference, Derived> p, std::nullptr_t);
 
 THRUST_NAMESPACE_END
 

thrust/detail/pointer.inl

@@ -34,8 +34,8 @@ template<typename Element, typename Tag, typename Reference, typename Derived>
 template<typename Element, typename Tag, typename Reference, typename Derived>
   __host__ __device__
   pointer<Element,Tag,Reference,Derived>
-    ::pointer(std::nullptr_t np)
-      : super_t(static_cast<Element*>(np))
+    ::pointer(std::nullptr_t)
+      : super_t(static_cast<Element*>(nullptr))
 {} // end pointer::pointer
 
 
@@ -180,30 +180,30 @@ operator<<(std::basic_ostream<charT, traits> &os,
 // `std::unique_ptr`.
 template <typename Element, typename Tag, typename Reference, typename Derived>
 __host__ __device__
-bool operator==(std::nullptr_t np, pointer<Element, Tag, Reference, Derived> p)
+bool operator==(std::nullptr_t, pointer<Element, Tag, Reference, Derived> p)
 {
-  return np == p.get();
+  return nullptr == p.get();
 }
 
 template <typename Element, typename Tag, typename Reference, typename Derived>
 __host__ __device__
-bool operator==(pointer<Element, Tag, Reference, Derived> p, std::nullptr_t np)
+bool operator==(pointer<Element, Tag, Reference, Derived> p, std::nullptr_t)
 {
-  return np == p.get();
+  return nullptr == p.get();
 }
 
 template <typename Element, typename Tag, typename Reference, typename Derived>
 __host__ __device__
-bool operator!=(std::nullptr_t np, pointer<Element, Tag, Reference, Derived> p)
+bool operator!=(std::nullptr_t, pointer<Element, Tag, Reference, Derived> p)
 {
-  return !(np == p);
+  return !(nullptr == p);
 }
 
 template <typename Element, typename Tag, typename Reference, typename Derived>
 __host__ __device__
-bool operator!=(pointer<Element, Tag, Reference, Derived> p, std::nullptr_t np)
+bool operator!=(pointer<Element, Tag, Reference, Derived> p, std::nullptr_t)
 {
-  return !(np == p);
+  return !(nullptr == p);
 }
 
 THRUST_NAMESPACE_END

thrust/device_ptr.h

@@ -92,7 +92,7 @@ class device_ptr
      *  \post <tt>get() == nullptr</tt>.
      */
     __host__ __device__
-    device_ptr(std::nullptr_t ptr) : super_t(ptr) {}
+    device_ptr(std::nullptr_t) : super_t(nullptr) {}
 
     /*! \brief Construct a \c device_ptr from a raw pointer which is
      *  convertible to \c T*.
@@ -153,9 +153,9 @@ class device_ptr
      *  \return \c *this.
      */
     __host__ __device__
-    device_ptr& operator=(std::nullptr_t ptr)
+    device_ptr& operator=(std::nullptr_t)
     {
-      super_t::operator=(ptr);
+      super_t::operator=(nullptr);
       return *this;
     }