message: Remove special const ptr version
diff: @@ -80,8 +80,6 @@ public:
  /// Device::UsingDevice() and the ptr state.
  template <class T>
  static inline T *ptr(T *a) { return static_cast<T*>(MM().Ptr(a)); }
  - template <class T>
  - static inline const T* ptr(const T *a) { return static_cast<const T*>(MM().Ptr(a)); }
  static inline memory &mem(const void *a) { return MM().maps.memories.at(a); }
  