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

[Benjamin Kosnik]

>In my opinion, the resolution of DR 60 is pretty clear: tellg and seekg
>require a sentry:
>
>    http://www.open-std.org/jtc1/sc22/wg21/docs/lwg-defects.html#60
>
>(about paragraphs 36-38 of 27.6.1.3)

Why doesn't istream just define tellg and seekg as seek members, neither
formatted nor unformatted io, as ostream does?

Ugh. Personally, I think this is a less than stellar idea: now istream
and ostream error behavior varies for seeking (istream will set
failbit, ostream won't.) Maybe this new behavior makes more sense, but
I think it's a toss-up when the inconsistency is factored in.

Anyway. 

If you are going to go ahead with this, it would probably be a good
idea to add ostream versions of

27_io/basic_istream/seekg/char/8348-1.cc

So we can track divergence.

-benjamin