Re: VStudio 2005 C++ compiler BUG ?

From:

"Victor Bazarov" <v.Abazarov@comAcast.net>

Newsgroups:

microsoft.public.vc.language

Date:

Wed, 15 Nov 2006 12:39:58 -0500

Message-ID:

<ejfjdf$3ig$1@news.datemas.de>

Alfredo wrote:

(paste this code into a Win32 console project and run it)
As it is, it does not execute any operator, but if you comment the
first two operators of Class1, then it executes the other one!
Is this a bug?

#include "stdafx.h"
#include <iostream>

class Class1
{
};

class Sample1
{
   public:

operator Class1() const
   {
       std::cout << "1" << std::endl;
       return *(new Class1());
   }
operator const Class1() const
   {
       std::cout << "2" << std::endl;
       return *(new Class1());
   }
operator const Class1 &() const
   {
       std::cout << "3" << std::endl;
       return *(new Class1());
   }
};

int _tmain(int argc, _TCHAR* argv[])
{
Sample1 s;
const Class1 &tmp=(const Class1 &)s;
}

Seems like a bug. If you drop the cast, you will find that
your conversion functions are considered by VC++ ambiguous.

C-style casts are very dangerous beasts. Here it hides the
fact that the compiler is incapable of picking the correct
conversion function.

------------------------ this code
class Sample
{
public:
    operator int() const { return 42; }
private:
    operator int const &() const { return *(new int(666)); }
};

int main()
{
    Sample s;
    const int &tmp = s;
}
-------------------------------------

Should give an error 'inaccessible operator int const&'. And if
you make that operator public as well, it should compile cleanly.

I suggest submitting this as a bug.

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask