There are plenty of cases where you'd prefer an application to crash upon an unhanded write error, rather than silently losing data that could be highly important and irrecoverable.

(Of course, actually handling the errors is preferred above both.)

> Destructors aren't supposed to fail.

But isn't the whole point of this discussion is that the destructor of fs::File (and probably any other buffered IO writer) can and does fail in some cases?

I think it could take a callback, so it could note the failure somewhere if I care about it.