Error on va_start and non-POD type

[Ritchard Nash]

Hi,
during a compilation the gcc 3.2.2 gave me this error:
---------------------------------------------------------
pdb.cc: In function `int pdbIsAvailable(TclInterp_cl&, ...)':
pdb.cc:233: cannot pass objects of non-POD type `class TclInterp_cl'
through
   `...'
pdb.cc:233: warning: second parameter of `va_start' not last named
argument
---------------------------------------------------------
The snippet of code that cause the error is :
----------------------------------------------------------
int pdbIsAvailable( TclInterp_cl& tcl, ... ) 
{ 
va_list ap; 
char *foo; 

TclInterp_cl &interp = (va_start(ap,tcl),tcl);   // line 233

int t; 
strcpy(pdbBuf, "[pdbIsAvailable "); 
while( (foo = va_arg(ap, char *)) != NULL ) { 
strcat(pdbBuf, foo); 
strcat(pdbBuf, " "); } va_end(ap); 
strcat(pdbBuf, "]"); 

Tcl_ExprBoolean( interp.GetInterp(), pdbBuf, &t ); 

return t;
}
---------------------------------------------------------
Where TclInterp_cl is a C++ wrapper of TclInterp from the Tcl source
code. TclInterp_cl is defined as non-POD type(because of a user-defined
destructor) but since it isn't actually passed trough "..." why the
complier complain that way ?
There are known bug about va_start ? 
Someone has ideas ? 

-- 
Best Regards,
Ritchard Nash <ritchard76@supereva.it>