Re: Any problems expected in Multiple inheritance with template class ?

From:
"Ganga Sridhar" <gangasridhar@abosoftware.com>
Newsgroups:
microsoft.public.vc.language
Date:
Fri, 11 Jul 2008 00:06:45 +0530
Message-ID:
<ejFxqvr4IHA.2072@TK2MSFTNGP04.phx.gbl>
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Sorry for the incomplete mail:

I have my derived class

CABIOleDbSet : public CCommand<TAccessor, TRowset>, public CABISet

{
....
}

In CABISet I have a function like this

class CABISet

{

..........

virtual void Open(const string& strSQL) = 0;

}

HRESULT CABIOleDbSet::OpenWithException(CABIOleDbSession& session, const =
string& strCmd, DBPROPSET *pPropSet)

{

if(session.IsOpen()==false)

{

ostringstream ost;

ost << "Session is not opened. Can'nt execute command [" << strCmd << =
"]";

throw CMyException(CONNECTION_ERROR, ost.str(), __FILE__, __LINE__);

}

wstring wstrCmd = StrToWstr(strCmd);

HRESULT hr = S_FALSE;

try

{

hr =CCommand::Open(*m_pSession, wstrCmd.c_str(), pPropSet);//CRASHES =
here

}

catch(...)

{

ASSERT(false);

}

return hr;

}

Any idea why?

Thanks and Regards

Ganga

"Igor Tandetnik" <itandetnik@mvps.org> wrote in message =
news:O6FGn0q4IHA.3484@TK2MSFTNGP05.phx.gbl...

"Ganga Sridhar" <gangasridhar@abosoftware.com> wrote in message
news:egVe9lp4IHA.5060@TK2MSFTNGP02.phx.gbl

When I use multiple inheritance i.e derived class CABIOleDBSet from
CCommand and CTest program crashes.

 
Crashes when doing what? I seem to have misplaced by crysal ball.
--
With best wishes,
   Igor Tandetnik
 
With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going to =

land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925
 


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<BODY>
<DIV>
<P><FONT face=Arial size=2>Sorry for the incomplete mail:</FONT></P>
<P><FONT face=Arial size=2>I have my derived class<FONT size=3>
</FONT></FONT></P>
<P><FONT face=Arial><FONT size=2><STRONG>CABIOleDbSet : public
CCommand&lt;TAccessor, TRowset&gt;, public
CABISet<BR></STRONG><BR>{<BR>...<BR>}<BR></FONT></P></FONT>
<P><FONT face=Arial size=2>In CABISet I have a function like this
</FONT></P><FONT face=Arial size=2><FONT color=#0000ff size=2>
<P>class</FONT><FONT size=2> CABISet </FONT></P>
<P><FONT size=2>{</FONT></P>
<P><FONT size=2>.........</P></FONT><FONT color=#0000ff size=2>
<P><STRONG>virtual</STRONG></FONT><STRONG><FONT size=2> </FONT><FONT
color=#0000ff size=2>void</FONT><FONT size=2> Open(</FONT><FONT =
color=#0000ff
size=2>const</FONT><FONT size=2> string&amp; strSQL) = =
0;</FONT></STRONG></P>
<P><FONT size=2>}</P></FONT></FONT>
<P><FONT face=Arial size=2><STRONG>HRESULT
CABIOleDbSet::OpenWithException(CABIOleDbSession&amp; session, const =
string&amp;
strCmd, DBPROPSET *pPropSet)</STRONG></FONT></P>
<P><FONT face=Arial size=2>{</FONT></P>
<P><FONT face=Arial =
size=2>if(session.IsOpen()==false)</FONT></P>
<P><FONT face=Arial size=2>{</FONT></P>
<P><FONT face=Arial size=2>ostringstream ost; </FONT></P>
<P><FONT face=Arial size=2>ost &lt;&lt; "Session is not opened. =
Can'nt execute
command [" &lt;&lt; strCmd &lt;&lt; "]";</FONT></P>
<P><FONT face=Arial size=2>throw CMyException(CONNECTION_ERROR, =
ost.str(),
__FILE__, __LINE__);</FONT></P>
<P><FONT face=Arial size=2>}</FONT></P>
<P><FONT face=Arial size=2>wstring wstrCmd = =
StrToWstr(strCmd);</FONT></P>
<P><FONT face=Arial size=2>HRESULT hr = S_FALSE;</FONT></P>
<P><FONT face=Arial size=2></FONT></P>
<P><FONT face=Arial size=2>try</FONT></P>
<P><FONT face=Arial size=2>{</FONT></P>
<P><FONT face=Arial size=2><STRONG>hr =CCommand::Open(*m_pSession, =

wstrCmd.c_str(), pPropSet);//CRASHES here</STRONG></FONT></P>
<P><FONT face=Arial size=2>}</FONT></P>
<P><FONT face=Arial size=2>catch(...)</FONT></P>
<P><FONT face=Arial size=2>{</FONT></P>
<P><FONT face=Arial size=2>ASSERT(false);</FONT></P>
<P><FONT face=Arial size=2>}</FONT></P>
<P><FONT face=Arial size=2>return hr;</FONT></P>
<P><FONT face=Arial size=2>}</FONT></P>
<P><FONT face=Arial size=2>Any idea why?</FONT></P>
<P><FONT face=Arial size=2>Thanks and Regards</FONT></P>
<P><FONT face=Arial size=2>Ganga</FONT></P></DIV>
<DIV><FONT face=Arial size=2>"Igor Tandetnik" &lt;</FONT><A
href="mailto:itandetnik@mvps.org"><FONT face=Arial
size=2>itandetnik@mvps.org</FONT></A><FONT face=Arial size=2>&gt; =
wrote in
message </FONT><A =
href="news:O6FGn0q4IHA.3484@TK2MSFTNGP05.phx.gbl"><FONT
face=Arial =
size=2>news:O6FGn0q4IHA.3484@TK2MSFTNGP05.phx.gbl</FONT></A><FONT
face=Arial size=2>...</FONT></DIV><FONT face=Arial size=2>&gt; =
"Ganga Sridhar"
&lt;</FONT><A href="mailto:gangasridhar@abosoftware.com"><FONT =
face=Arial
size=2>gangasridhar@abosoftware.com</FONT></A><FONT face=Arial =
size=2>&gt; wrote
in message<BR>&gt; </FONT><A
href="news:egVe9lp4IHA.5060@TK2MSFTNGP02.phx.gbl"><FONT face=Arial
size=2>news:egVe9lp4IHA.5060@TK2MSFTNGP02.phx.gbl</FONT></A><BR><FONT =
face=Arial
size=2>&gt;&gt; When I use multiple inheritance i.e derived class =
CABIOleDBSet
from<BR>&gt;&gt; CCommand and CTest program crashes.<BR>&gt; <BR>&gt; =
Crashes
when doing what? I seem to have misplaced by crysal ball.<BR>&gt; -- =
<BR>&gt;
With best wishes,<BR>&gt;&nbsp;&nbsp;&nbsp; Igor Tandetnik<BR>&gt; =
<BR>&gt; With
sufficient thrust, pigs fly just fine. However, this is not <BR>&gt; =
necessarily
a good idea. It is hard to be sure where they are going to <BR>&gt; =
land, and it
could be dangerous sitting under them as they fly <BR>&gt; overhead. -- =
RFC 1925
<BR>&gt; <BR>&gt;</FONT></BODY></HTML>

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