Re: std::max: if versus ?:

[Paolo Carlini <paolo dot carlini at oracle dot com>]

On 09/20/2012 02:06 PM, Paolo Carlini wrote:
> On 09/20/2012 01:55 PM, Marc Glisse wrote:
> > Hello,
> >
> > I noticed that std::max is implemented as:
> >
> >       //return  __a < __b ? __b : __a;
> >       if (__a < __b)
> >         return __b;
> >       return __a;
> >
> > Notice how it doesn't use the ?: code but the "if" version instead. 
> > Looking at the history, this seems to come from SGI. Does someone 
> > know why it was done this way?
> I'm going to tell you something very vague and non technical, but in 
> the past, outside std::max, I had quite often to use the above instead 
> of a conditional operator as a second thought, when (maybe on a less 
> common target) a test "unexpectedly" failed with a conversion error. 
> Does that help you figuring out the technical details of the issue?
As a matter of fact, in the case of std::max as specified in the Std, 
thus with a single template parameter used in the three places, I don't 
see what may go wrong with ?: thus personally I'm back to square one ;) 
But maybe there is something subtle which I'm still not seeing.

Paolo.