Re: std::stringstream returning back values

From:

"Daniel T." <daniel_t@earthlink.net>

Newsgroups:

comp.lang.c++

Date:

Tue, 08 Jan 2008 22:07:51 -0500

Message-ID:

<daniel_t-60B5A2.22075108012008@earthlink.vsrv-sjc.supernews.net>

In article
<32f67c60-fcdf-4fb6-8974-dd0d59fc2103@e4g2000hsg.googlegroups.com>,
TBass <tbj@automateddesign.com> wrote:

Hi.

I wrote a "tag" class to store values. The user gets to store most any
type he would need. Instead of getting too complicatated, I decided I
would store the value as a stringstream, then overload the SetValue
method.

...

protected:
     std::stringstream m_szValue;

...

void
CFusionTag::SetValue( char *szValue )
{
        m_szValue << szValue;

        MessageBox::Show( m_szValue.str().c_str() );

} /* ::SetValue */

void
CFusionTag::SetValue( unsigned int uiValue )
{
        m_szValue << uiValue;
}

void
CFusionTag::SetValue( int iValue )
{
        m_szValue << iValue;
}

void
CFusionTag::SetValue( float fValue )
{
        m_szValue << fValue;
}

void
CFusionTag::SetValue( double dValue )
{
        m_szValue << dValue;
}

void
CFusionTag::SetValue( long lValue )
{
        m_szValue << lValue;
}

That works fine (I'm aware of the obvious flaw in this code, but I use
taking advantage of that for debugging purposes). The value gets
stored.

My problem (which is probably obvious to everyone but me) is returning
the value when someone calls the GetValue method.

void
CFusionTag::GetValue( char *szValue )
{

        MessageBox::Show( "Sending back a char value!" );
        szValue = (char *)m_szValue.str().c_str();
}

The char string returned is always blank.

Your not returning anything. Try this:

std::string
CFusionTag::GetValue() const
{
return m_szValue.str();
}

I thought this would be pretty simple, but STL keeps getting the
better of me. Can anyone point me in the right direction?

Your having problems because you are trying to use C idioms (char*)
instead of C++ idioms (string.)