Re: [v3] Fix second half of libstdc++/6745

[Gabriel Dos Reis <gdr at integrable-solutions dot net>]

Paolo Carlini <pcarlini@unitus.it> writes:

| Hi Benjamin and Jonathan and everyone!
| 
| >>A potentially much simpler solution occured to me.  Could we declare that
| >>Paolo's original patch (the one that started this thread) only applies to
| >>cin?  I.e., make the condition this:
| >>   if (__sbin == cin->rdbuf() && isatty(0))
| >>
| >Hey y'all. I think a better way to think about this is that the
| >streambuf is unbuffered. That way you don't have to deal with the isatty
| >issue. (For unbuffered streams, _M_buf_size_opt == 0)
| >
| >If you do the checks based on that I think it will be cleaner.
| >
| Interesting, thanks.
| I'm planning to work harder on this, following Jonathan ideas, in the
| next few days.
| 
| However I can already confirm that the idea basically *works*! I mean,
| a gross implementation
| using reinterpret_cast<basic_streambuf<char/wchar_t>* > to compare
| __sbin to cin and wcin

Please don't do that because that won't solve the problem, I think.

Basically, the thing is that being attached with a TTY is a *dynamic*
property that can potientially happen at any time to thingies that are
not just cin ou variants.

-- Gaby