Re: [Algorithms] How to get 3dvector largest coordinate index?

[Charles N. <cha...@gm...>]

cast-through-union does violate the standard, but I think it's one of those
decisions where you draw the line at "what works on all of the compilers _i_
use" vs "conforming to the standard as written".  We're not all working on
boost! (thank god)  :-D
-charles

On Tue, Mar 3, 2009 at 10:08 PM, Alen Ladavac <ale...@cr...> wrote:

> Thanks. A template is a nice approach for abstracting this. Btw, I'd
> add a static_assert(sizeof(U)==sizeof(T)) there.
>
> But isn't union a not-completely-legal way to do this? From the
> remainder of the thread and from some experimentation, I'd say that
> the best way would be to use memcpy()...
>
> Alen
>
> Pal-Kristian wrote at 3/3/2009:
>
> > Try this useful template:
>
> > template<typename T, typename U>
> > static T bit_cast(const U val)
> > {
> >     union { U u; T t; } bits = { val };
> >     return bits.t;
> > }
>
> > Now:
> >     float f = ...;
> >     uint32_t u = bit_cast<uint32_t>(f);
>
> > Should work.
>
> > Alen Ladavac wrote:
> >> christer wrote at 3/3/2009:
> >>
> >>> It's not unusual, but most attempts to do so are most certainly
> >>> undefined. As already witnessed in this thread! ;P
> >>>
> >>
> >> What is your recommendation for a portable way to obtain a float's bits
> >> as an integer?
> >>
> >> Thanks,
> >> Alen
> >>
> >>
> >>
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>
>
>
>
> --
> Alen
>
>
>
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