[lug] C++ libraries in Linux

[Scott A. Herod]

I knew that I shouldn't post any source code and show off how badly
I write. :-(

Looking at the gcc3 headers, it doesn't appear that they've yet
incorporated
stringstream.

The destructor for the strstream class is defined as so:
strstream::~strstream() {}

In the strstreambuf destructor it appears that the char* buffer is only
freed if the stream is not frozen:

strstreambuf::~strstreambuf()
{
  if (_M_dynamic && !_M_frozen)
    _M_free(eback());  // eback() apparently returns a pointer to the
	               // front of the buffer
}

So, I think now that my code should be:

> #include <strstream>
> string paraNode::toString()
> {
>     string rtnval;
>     strstream buf;
>
>     buf << "Paragraph: "
>         << ATTR_ALIGN << " = " << _align << ", "
>         << ATTR_WRAP_MODE << " = " << _mode
>         << ends;
>     rtnval = buf.str();

      buf.freeze( false );

>     return rtnval;
> }

Keeping in the original thread; no comments on this subject at
dinkumware.

http://www.dinkumware.com/htm_cpl/strstrea.html

Scott

Keith Brown wrote:
> 
> I hate to reply to my own mail, but my example is not correct.  The buf should be
> unfrozen with buf.freeze(false), at least according to Josuttis.  Additionally,
> strstream has been depreciated and he suggest you use stringstream.
> 
> Keith
> 
> Keith Brown wrote:
> 
> > Hi,
> >
> > I believe you have memory leak in your example.  Once you do buf.str(), the
> > program owns the *char that is returned, unless it tells strstream otherwise,
> > which I forget how to do.  I believe you need to do it like:
> >
> > char * s = buf.str();
> > rtnval = s;
> > delete [] s;
> > return rtnval;
> >
> > Keith
> >
> > "Scott A. Herod" wrote:
> >
> > > Hi,
> > >   I use something like the following:
> > >
> > > #include <strstream>
> > > string paraNode::toString()
> > > {
> > >     string rtnval;
> > >     strstream buf;
> > >
> > >     buf << "Paragraph: "
> > >         << ATTR_ALIGN << " = " << _align << ", "
> > >         << ATTR_WRAP_MODE << " = " << _mode
> > >         << ends;
> > >
> > >     rtnval = buf.str();
> > >     return rtnval;
> > > }
> > >