Re: CVS commit: [riastradh-drm2] src/sys/external/bsd/drm2/include/linux

[Alan Barrett <apb%cequrux.com@localhost>]

On Wed, 24 Jul 2013, Taylor R Campbell wrote:
> Modified Files:
>         src/sys/external/bsd/drm2/include/linux [riastradh-drm2]: kernel.h
>
> Log Message:
> Implement bogus max_t in <linux/kernel.h>.

> +/* XXX These will multiply evaluate their arguments.  */
> +#define        max_t(T, X, Y)  MAX(X, Y)
> #define min_t(T, X, Y)  MIN(X, Y)

If we are willing to use the non-standard ({ ... }) syntax, then 
these can be written to evaluate their arguments only once, like 
this:

    #define max_t(T, X, Y) ({ T _x = (X), _y = (Y); (_x > _y ? _x : _y); })
    #define min_t(T, X, Y) ({ T _x = (X), _y = (Y); (_x < _y ? _x : _y); })

--apb (Alan Barrett)