Re: [Boost-users] [BULK] Re: [range] From 1.33.0 gives new warningvs 1.32

From: David Abrahams (dave_at_[hidden])
Date: 2005-08-15 16:54:39

"Thorsten Ottosen" <nesotto_at_[hidden]> writes:

>> > > perhaps something like this is needed?
>> >
>> > >          template< class Char >
>> > >          inline Char* str_end( Char* s )
>> > >          {
>> > > -            return (Char*)str_end( s, s );
>> > > +            return const_cast<Char*>(str_end( s, s ));
>> >
>> > what's the difference? A c-style cast is also a const-cast.
>>
>> You didn't just say that.
>
> Apparently I did.

I must admit I was surprised, too.

> What's the difference in the generated object code?

Thorsten, the difference is in fragility over time with maintenance.
That's why the compiler issues the warning.  Any decent beginner's
book on C++ will advise you to eschew all casts, and prefer the
new-style ones.  Do you really need to have the fundamentals of good
C++ programming practice explained?

Incidentally, if you find that the proper C++ construct is "less
portable. somehow." you should use BOOST_WORKAROUND to isolate the
compiler for which it fails to work, if only so that the reason for
the workaround is documented.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com