corelinux-develop

[Corelinux-develop] exception and inheritance

[Christophe Prud'h. <pru...@MI...>]

YAROGT again!

I cannot verify this in a C++ textbook/reference, I don't have one handy
but

say that we have 
class A
{
public:
  virtual void f() throw(exceptA);
}

class B : public A
{
  public:

// f redefined
void f(); // is it ok?
void f() throw(exceptA); // or is it this one? or both?

}

it seems that in 2.96 the first one is rejected 
the second one is the correct one
I would say that the true prototype is the second one
the first one is another function which does not throw any exceptions

any c++ guru?
I miss my stroustrup badly now

in ex6 I got a compilation problem whith that!

C.
-- 
   Christophe Prud'homme                  |
   MIT, 77, Mass Ave, Rm 3-243            |   I respect faith, but doubt is
   Cambridge MA 02139                     |   what gives you an education.
   Tel (Office) : (00 1) (617) 253 0229   |   -- Wilson Mizner
   Fax (Office) : (00 1) (617) 258 8559   |
   http://augustine.mit.edu/~prudhomm     |
                          Following the hacker spirit

Re: [Corelinux-develop] exception and inheritance

[Frank V. C. <fr...@co...>]

Christophe Prud'homme wrote:
> 
> YAROGT again!
> 
> I cannot verify this in a C++ textbook/reference, I don't have one handy
> but
> 
> say that we have
> class A
> {
> public:
>   virtual void f() throw(exceptA);
> }
> 
> class B : public A
> {
>   public:
> 
> // f redefined
> void f(); // is it ok?
> void f() throw(exceptA); // or is it this one? or both?
> 
> }
> 
> it seems that in 2.96 the first one is rejected
> the second one is the correct one
> I would say that the true prototype is the second one
> the first one is another function which does not throw any exceptions

This is a very good thing! 

> 
> any c++ guru?
> I miss my stroustrup badly now
> 
> in ex6 I got a compilation problem whith that!

Great! We want to add the correct signatures now. I get lazy, and now
the compiler forces me to do it right. I love it.

Are you entering defects for these? That way you aren't saddled with all
the work. The other thing is that any changes made can NOT cause errors
with 2.95.2
> 
> C.
> --
>    Christophe Prud'homme                  |
>    MIT, 77, Mass Ave, Rm 3-243            |   I respect faith, but doubt is
>    Cambridge MA 02139                     |   what gives you an education.
>    Tel (Office) : (00 1) (617) 253 0229   |   -- Wilson Mizner
>    Fax (Office) : (00 1) (617) 258 8559   |
>    http://augustine.mit.edu/~prudhomm     |
>                           Following the hacker spirit
> 
> _______________________________________________
> Corelinux-develop mailing list
> Cor...@li...
> http://lists.sourceforge.net/mailman/listinfo/corelinux-develop

-- 
Frank V. Castellucci
http://corelinux.sourceforge.net
OOA/OOD/C++ Standards and Guidelines for Linux
http://PythPat.sourceforge.net
Pythons Pattern Package

Re: [Corelinux-develop] exception and inheritance

[Christophe Prud'h. <pru...@MI...>]

> Great! We want to add the correct signatures now. I get lazy, and now
> the compiler forces me to do it right. I love it.
I did that 
the port to 2.96 is complete and working

>
> Are you entering defects for these? That way you aren't saddled with all
> the work. The other thing is that any changes made can NOT cause errors
> with 2.95.2
I'll do that
I check that everything( the examples) is working with 2.96 but not 2.95
a priori there should be no problems since the code is c++ correct now
but I'll verify that also before commiting 
first step create defects
- port to 2.96 ?
- ensure C++ correctness ?

-- 
   Christophe Prud'homme                  |
   MIT, 77, Mass Ave, Rm 3-243            |   I respect faith, but doubt is
   Cambridge MA 02139                     |   what gives you an education.
   Tel (Office) : (00 1) (617) 253 0229   |   -- Wilson Mizner
   Fax (Office) : (00 1) (617) 258 8559   |
   http://augustine.mit.edu/~prudhomm     |
                          Following the hacker spirit

Re: [Corelinux-develop] exception and inheritance

[Gabriel D. R. <Gab...@cm...>]

"Christophe Prud'homme" <pru...@MI...> writes:

| YAROGT again!
| 
| I cannot verify this in a C++ textbook/reference, I don't have one handy
| but
| 
| say that we have 
| class A
| {
| public:
|   virtual void f() throw(exceptA);
| }
| 
| class B : public A
| {
|   public:
| 
| // f redefined
| void f(); // is it ok?

No this is wrong.

| void f() throw(exceptA); // or is it this one? or both?

This one is OK.
| 
| }
| 
| it seems that in 2.96 the first one is rejected 
| the second one is the correct one
| I would say that the true prototype is the second one
| the first one is another function which does not throw any exceptions
| 
| any c++ guru?

I'm not a C++ guru but I'll answer it anyway.  Since a virtual
function speficies responsabilities, its overriders cannot safely
allow more exceptions that the initial interface does.

I'd strongly recommand not to use exception-specification -- the
exception (no pun intended) might be throw().

-- Gaby