Maybe we could have two levels

 -wxs1 - whatever meaningful definition of non-POD types being caught by
value (not reference or ptr)
 -wxs2 - any type other than fundamental types being caught by value (not
reference or ptr)

For myself I'd use -wxs2 all the time



"Heinz Saathoff" <hsaat@bre.ipnet.de> wrote in message news:MPG.19b3f7e93fbe82389896cf@news.digitalmars.com...
> Walter schrieb...
> >
> > Hmm. I would think that a POD type would be defined by not having a
vptr.
>
> Not only that struct but also included structs. The standard says that PODs are classic C-structs which makes sense. This also gives compiler writes more freedom in implementing things. For DMC I know that adding members isn't a problem and I still can memcpy such structs. But it's not guaranteed by the standard.
>
> - Heinz

"Matthew Wilson" <matthew@stlsoft.org> a écrit dans le message de news:bicnia$938$1@digitaldaemon.com...
> Maybe we could have two levels
>
>  -wxs1 - whatever meaningful definition of non-POD types being caught by
> value (not reference or ptr)
>  -wxs2 - any type other than fundamental types being caught by value (not
> reference or ptr)
>
> For myself I'd use -wxs2 all the time
>

IMO, the second option is enough... Even for POD type, you should catch
them by reference as it is possible to derive from a structure and will then
have the slicing problem again if you throw again the exception. I don't see
much benefit in catch by value.... but then what is the difference with
passing
parameters to a function by value!

"Philippe Mori" <philippe_mori@hotmail.com> wrote in message news:biirgo$ida$1@digitaldaemon.com...
>
> "Matthew Wilson" <matthew@stlsoft.org> a écrit dans le message de news:bicnia$938$1@digitaldaemon.com...
> > Maybe we could have two levels
> >
> >  -wxs1 - whatever meaningful definition of non-POD types being caught by
> > value (not reference or ptr)
> >  -wxs2 - any type other than fundamental types being caught by value
(not
> > reference or ptr)
> >
> > For myself I'd use -wxs2 all the time
> >
>
> IMO, the second option is enough... Even for POD type, you should catch them by reference as it is possible to derive from a structure and will
then
> have the slicing problem again if you throw again the exception. I don't
see
> much benefit in catch by value.... but then what is the difference with
> passing
> parameters to a function by value!

Well, one thing with pbv is that it is a must when used on iterators in algorithms.

Overall, I agree that only the second would be of use to me, but I was just wanting to cater for sloppy programmers and hard-pressed compiler implementers

>
> Well, one thing with pbv is that it is a must when used on iterators in algorithms.
>

It is for catch clauses that pass-by-value has no reel value for me... For other cases like function parameters, it is different.