How to abort gRPC streaming on error and indicate the error in C++

I'm sending a synchronous stream of gRPC messages from a client written in C++, in the following sequence:

• Obtain an unique_ptr to a ClientWriter
• Call its Write() method with messages as many times as needed.
• Call its WritesDone() method
• Call Finish() to obtain the server's status.

How would I abort this sequence in case of a client-side error and indicate that to the server?