file stream tellg/tellp and gcc-4.6 is this a bug?

Question

This code:

#include 
#include 
#include 
#include 

int main()
{   
    std::remove(\"test.txt\");         


        

Answer 1

Ok, separate from the version analysis, which I'll leave for good measure, here is the answer:

PR/26211

I'll try to find source, but this thread discusses whether the documentation needs to be updated due to this change. It is therefore, a documented change :)

Edit Only found this: libstdc++/26211 (again) + N3168

From this page: http://gcc.gnu.org/ml/libstdc++/2011-04/msg00026.html

Hey, all.

I recently started using gcc-4.6.0 and it seems that the behaviour of std::istream::tellg() has changed when (just) the eofbit is set. I managed to track this down to PR/26211, and I'm not debating the changes.

It took me a while to figure out what was wrong because the doxygen for tellg() says:

If fail() is not false, returns pos_type(-1) to indicate
failure. Otherwise returns rdbuf()->pubseekoff(0,cur,in).

That's almost word for word what Langer and Kreft says, so I'm presuming DR60's change to 27.6.1.3 paragraph 37 has lead to this change in libstdc++ behaviour.

Should the libstdc++ doxygen be updated to say something about the fact that calling tellg()when eof() will also return pos_type(-1) (because of the fact that it constructs a sentry)? Are there other functions that also should have updated documentation as a result of DR60?