Paper N3778 added the following two deallocation signatures to the standard library:

   void operator delete(void* ptr, std::size_t size,
                        const std::nothrow_t&) noexcept;
   void operator delete[](void* ptr, std::size_t size,
                          const std::nothrow_t&) noexcept;

The core language does not currently provide for calling these functions; they could only be called as the matching deallocation function when a constructor throws an exception, but the rules for determining the matching deallocation function do not consider the existence of the sized-deallocation variants.