[Bug libstdc++/57273] New: stringstream str initialization fails

[Bug libstdc++/57273] New: stringstream str initialization fails

[ycollette.nospam at free dot fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57273

            Bug ID: 57273
           Summary: stringstream str initialization fails
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libstdc++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: ycollette.nospam at free dot fr

It tried to initialize the content of a stringstream using the following code:

std::stringstream tmpLabel;

tmpLabel.str("test ");
tmpLabel << 1;

And the result fails. I've got on screen: '1est' instead of 'test 1'.

The workaround:

std::stringstream tmpLabel;

tmpLabel.str("");
tmpLabel << "test " << 1;

Here is a test file:

#include <iostream>
#include <sstream>

int main()
{
        std::stringstream tmp;

        tmp.str("test\0");

        tmp << 1;

        std::cout << "result = |" << tmp.str() << "|" << std::endl;

        tmp.str("");

        tmp << "test " << 1;

        std::cout << "result = |" << tmp.str() << "|" << std::endl;

        return 0;
}

[Bug libstdc++/57273] stringstream str initialization fails

[ycollette.nospam at free dot fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57273

collette <ycollette.nospam at free dot fr> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Version|unknown                     |4.6.3

--- Comment #1 from collette <ycollette.nospam at free dot fr> ---
I use mageia2 64 bits with gcc-4.6.3.

[Bug libstdc++/57273] stringstream str initialization fails

[ycollette.nospam at free dot fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57273

--- Comment #2 from collette <ycollette.nospam at free dot fr> ---
Just tested with gcc-4.8.0 compiled from scratch and the bug is still here.

[Bug libstdc++/57273] stringstream str initialization fails

[paolo.carlini at oracle dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57273

Paolo Carlini <paolo.carlini at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |INVALID

--- Comment #3 from Paolo Carlini <paolo.carlini at oracle dot com> ---
And this is not a bug, it's conforming behavior.

[Bug libstdc++/57273] stringstream str initialization fails

[ycollette.nospam at free dot fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57273

--- Comment #4 from collette <ycollette.nospam at free dot fr> ---
Oups. OK, I just tested with intel c++ compiler and the behavior is the same.
Where is this behavior defined ?

[Bug libstdc++/57273] stringstream str initialization fails

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57273

--- Comment #5 from Jonathan Wakely <redi at gcc dot gnu.org> ---
[stringbuf.members]/3

[Bug libstdc++/57273] stringstream str initialization fails

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57273

--- Comment #6 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Which also explains that you can make the inserted characters append to the
buffer using std::ios::ate

e.g.
  std::stringstream tmpLabel(std::ios::ate|std::ios::out);

or using an ostringstream
  std::ostringstream tmpLabel(std::ios::out);

[Bug libstdc++/57273] stringstream str initialization fails

[ycollette.nospam at free dot fr]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57273

--- Comment #7 from collette <ycollette.nospam at free dot fr> ---
Thanks for these informations. Sorry for the noise.