TBH I think this is pure laziness. I looked at OpenSubdiv extensively. There are no good reasons to use signed in the cases I opened the ticket for and making

TBH I think this is pure laziness. I looked at OpenSubdiv extensively. There are no good reasons to use signed in the cases I opened the ticket for and making sure the code inside the lib does the right thing with unsigned arithmetic is trivial. But someone still needs to do that and writing that "Google (essentially) says you don't need to" in their style guide is much less work. ;-)