AW: [omniORB] fixed-length structs

[Sean Parker]

Wernke -

  It didn't generate the wrong sig - I was going on my
previous usage when the struct WAS variable length - all of
mine had been up till this point...

  Thanks for the info on the idl compiler option.

  Sean

--- Wernke zur Borg <wernke.zur.borg at vega.de> wrote:

> 
> I am only wondering why the IDL compiler has generated
> the wrong function signature... ;-)
> 
> Just a hint: Always use the -Wbexample option of omniidl
> to generate your function skeletons. This prevents you
> from mistyping the signatures.
> 
> Wernke
> 
> 
> > -----Original Message-----
> > From: omniorb-list-bounces at omniorb-support.com 
> > [mailto:omniorb-list-bounces at omniorb-support.com] On
> Behalf 
> > Of Sean Parker
> > Sent: 11 July 2007 13:50
> > To: Fischer, Clemens; omniorb-list at omniorb-support.com
> > Subject: Re: AW: [omniORB] fixed-length structs 
> > 
> > 
> > Thanks so much - I'll try it...
> > 
> >   Sean
> > 
> > --- "Fischer, Clemens"
> > <clemens.fischer at atlas-elektronik.com> wrote:
> > 
> > > Hi,
> > > 
> > > the difference in fixed-length and variable-length
> > > structs is that the former ones are returned by
> value,
> > > not by pointer. Yet another of the thousand pitfalls
> in
> > > the IDL to C++ mapping.
> > > 
> > > In case your get() method is an implemetatation of a
> > > CORBA interface method, the correct signature would
> be
> > > DateTime get( <stuff> ). It's also not necessary to
> > > create a DateTime instance on the heap. You can
> simply do
> > > it like this:
> > > 
> > >   DateTime get( <stuff> )
> > >   {
> > >     DateTime ret;
> > >     ret.year = 2007;
> > >     ...
> > >     ret.seconds = 0;
> > >     return ret;
> > >   }
> > > 
> > > So you don't need the _var type at all. I guess it's
> only
> > > there for symmetry and in case you later want to make
> the
> > > struct variable-length without changing your code.
> > > 
> > > If you take a look at _CORBA_ConstrType_Fix_Var,
> you'll
> > > notice that it handles its content by value instead
> of
> > > pointer and immediately deletes the value passed as
> > > pointer to its contructor.
> > > 
> > > Kind Regards
> > > Clemens Fischer
> > > 
> > > 
> > > -----Ursprüngliche Nachricht-----
> > > Von: omniorb-list-bounces at omniorb-support.com
> > > [mailto:omniorb-list-bounces at omniorb-support.com] Im
> > > Auftrag von Sean Parker
> > > Gesendet: Mittwoch, 11. Juli 2007 02:08
> > > Betreff: [omniORB] fixed-length structs 
> > > 
> > > Hello -
> > > 
> > >   I've encountered an issue simply because I'm trying
> to
> > > use a struct for the first that is "fixed length"
> (i.e.
> > > it's a series of longs, w/o a string in it)
> > > 
> > >   For example, I define a struct:
> > > 
> > > [Begin IDL]
> > >   struct DateTime
> > >   {
> > >     long year;
> > >     ...
> > >     long seconds;
> > >   };
> > > [End IDL]
> > > 
> > >   This results in C++ template using the *_Fix_*
> class (I
> > > forget the exact name) as opposed to the *_Variable_*
> > > template class if the struct had a string in it.
> > > 
> > > [Begin C++]
> > >   DateTime* get( <stuff> )
> > >   {
> > >     DateTime_var ret = new DateTime();
> > >     ret->year = 2007;
> > >     ...
> > >     ret->seconds = 0;
> > >     return ret._retn();
> > >   }
> > > [End C++]
> > > 
> > >   Now the compile complains "can't convert DateTime
> to
> > > DateTime* in return" on return line.
> > >  
> > >  I never had this problem when the template class was
> for
> > > variable-length structs. Am I doing something wrong?
> > > 
> > >  Any assistance appreciated.
> > > 
> > >   Thanks and God Bless
> > >     Sean
> > > 
> 





God Bless 
    Sean Parker 





       
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