Re: Using C++ in GCC is OK

[Paolo Bonzini <bonzini at gnu dot org>]

On 06/02/2010 03:54 PM, Ian Lance Taylor wrote:
> Richard Guenther<richard.guenther@gmail.com>  writes:
>
> > On Tue, Jun 1, 2010 at 6:58 PM, Ian Lance Taylor<iant@google.com>  wrote:
> > > Richard Guenther<richard.guenther@gmail.com>  writes:
> > >
> > > > Overall the wiki document looks good.  I'd like to disallow
> > > >
> > > > * Operators may only be overloaded for types which implement numeric
> > > > values, where the overloaded operators implement the usual numeric
> > > > semantics.
> > > >
> > > > though.
> > >
> > > My thinking here is that it would be reasonable to implement
> > > real_arithmetic and mpfr/mpc using overloaded operators.  I could
> > > certainly be wrong.
> >
> > It will hide the cost which is IMHO not wanted.
>
> I agree that that is the usual problem with overloaded operators.  I
> don't really agree that that is a problem in this specific case.  We
> have to do those operations anyhow.  I don't think the ease of writing
> the code is going to cause us to do extra operations in the target
> floating point format.

As mentioned elsewhere in this huge thread, I'd like to allow operator++ 
(preincrement), operator==, operator!= and operator* (unary) for 
iterators.  That is, only forward input operators.  We're going to use 
them anyway for the STL, so we might as well use them for bitmaps etc.

Paolo