Michael Greenberg wrote:
>
> My understanding (from april 95 draft) is that the following is ambiguous:
>
> class bar;
> foo(bool) ;
> foo(void*) ;
> void mumble(bar* b)
> {
>   foo(b) ;  // ambiguous
> }
>
> Is this [still] true?
>
> Assuming that it is, does it make sense to treat a
>   conversion of a pointer to a void*
> as better than a
>   conversion of a pointer to a bool?
>
> If not, that means it is not so useful  (w/o using casts) to overload a
> function on void* and bool (i.e. operator<<)

That's not my understanding:

A* -> void* and A* -> bool are both std conversions with the same
rank (conversion) but 13.3.3.2.4 says:

 --A  conversion  that  is not a conversion of a pointer, or pointer to
   member, to bool is better than another conversion  that  is  such  a
   conversion.

So foo (void*) should be choosed.

--

Valentin Bonnard
mailto:bonnardv@pratique.fr
http://www.pratique.fr/~bonnardv (Informations sur le C++ en Francais)


[ comp.std.c++ is moderated.  To submit articles: try just posting with      ]
[ your news-reader.  If that fails, use mailto:std-c++@ncar.ucar.edu         ]
[ FAQ:      http://reality.sgi.com/employees/austern_mti/std-c++/faq.html    ]
[ Policy:   http://reality.sgi.com/employees/austern_mti/std-c++/policy.html ]
[ Comments? mailto:std-c++-request@ncar.ucar.edu                             ]

My understanding (from april 95 draft) is that the following is ambiguous:

class bar;
foo(bool) ;
foo(void*) ;
void mumble(bar* b)
{
  foo(b) ;  // ambiguous
}

Is this [still] true?

Assuming that it is, does it make sense to treat a
  conversion of a pointer to a void*
as better than a
  conversion of a pointer to a bool?

If not, that means it is not so useful  (w/o using casts) to overload a
function on void* and bool (i.e. operator<<)


--
Michael Greenberg                      email: mgreenberg@scr.siemens.com
Siemens Corporate Research             phone: 609-734-3347
755 College Road East                  fax: 609-734-6565
Princeton, NJ 08540
---
[ comp.std.c++ is moderated.  To submit articles: try just posting with      ]
[ your news-reader.  If that fails, use mailto:std-c++@ncar.ucar.edu         ]
[ FAQ:      http://reality.sgi.com/employees/austern_mti/std-c++/faq.html    ]
[ Policy:   http://reality.sgi.com/employees/austern_mti/std-c++/policy.html ]
[ Comments? mailto:std-c++-request@ncar.ucar.edu                             ]