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

[<chr...@pl...>]

Jeff Russell wrote:

> if cast-through-union violates the standard, then why are unions in
> the language? isn't storing bytes and interpreting them as different
> types what unions are for?

No, that's not what unions are for. Unions are there to allow
you to store different type data in the same memory location
at DIFFERENT (nonoverlapping) TIMES.

Standard-violating aliasing is when you have different type
data in the same memory location at the SAME TIME.

The standard disallows same-time different-type aliasing,
because disallowing it allows for a lot of optimization
opportunities. This is a GOOD THING -- except programmers
need to learn to write standard-conforming code (which is
also a GOOD THING).


Christer Ericson, Director of Tools and Technology
Sony Computer Entertainment, Santa Monica