I think I meant to write "big pidfiles" there. With xsize_t() gc would die when seeing a pidfile whose size doesn't fit into size_t. The version I sent just ignores such files. However, it would choke on slightly smaller files that happen to not fit into memory. And no reasonable pidfile can be big enough to trigger any of that, so dying on conversion error wouldn't really be a problem. Is that what you meant? It makes sense, in any case.
In short: Yes.
Thanks, René