[RFC] DR 60 about tellg, seekg not implemented?

[Benjamin Kosnik]

>While investigating this issue, I noticed that libstdc++/8348 is exactly
>about it: we were doing the right thing (in my understanding) but we
>removed the sentry in order to answer libstdc++/8348.
>
>Therefore, adding back the sentry means, basically, reverting the commit
>for 8348: see attached draft patch.

Can you hang on a bit with this? I'm not in a place I can look at this
right now, and would like a chance to review this issue.

best,
-benjamin