How would one accomplish the following in D?

<snip from metronome twister rng>
#define MATRIX_A 0x9908b0dfUL   /* constant vector a */
#define UMASK 0x80000000UL /* most significant w-r bits */
#define LMASK 0x7fffffffUL /* least significant r bits */
#define MIXBITS(u,v) ( ((u) & UMASK) | ((v) & LMASK) )
#define TWIST(u,v) ((MIXBITS(u,v) >> 1) ^ ((v)&1UL ? MATRIX_A : 0UL))
</snip from metronome twister rng>

I read the "Converting C to D" and "The C Preproscesor vs D" pages but did not find a clear-cut example for the above cases.

thanks in advance,
Andrew

"Andrew Edwards" <edwardsac@spamfreeusa.com> wrote in message news:be4i4q$2vdt$1@digitaldaemon.com...
> How would one accomplish the following in D?
>
> <snip from metronome twister rng>
> #define MATRIX_A 0x9908b0dfUL   /* constant vector a */
> #define UMASK 0x80000000UL /* most significant w-r bits */
> #define LMASK 0x7fffffffUL /* least significant r bits */
> #define MIXBITS(u,v) ( ((u) & UMASK) | ((v) & LMASK) )
> #define TWIST(u,v) ((MIXBITS(u,v) >> 1) ^ ((v)&1UL ? MATRIX_A : 0UL))
> </snip from metronome twister rng>
>
> I read the "Converting C to D" and "The C Preproscesor vs D" pages but did not find a clear-cut example for the above cases.

const uint MATRIX_A = 0x9908b0df;   /* constant vector a */
const uint UMASK = 0x80000000; /* most significant w-r bits */
const uint LMASK = 0x7fffffff; /* least significant r bits */
const uint MIXBITS(uint u, uint v) { return (u & UMASK) | (v & LMASK); }
const uint TWIST(uint u,uint v) { return (MIXBITS(u,v) >> 1) ^ (v&1 ?
MATRIX_A : 0); }

"Walter" <walter@digitalmars.com> wrote...

> const uint MIXBITS(uint u, uint v) { return (u & UMASK) | (v & LMASK); }
> const uint TWIST(uint u,uint v) { return (MIXBITS(u,v) >> 1) ^ (v&1 ?
> MATRIX_A : 0); }
>

Thanks Walter,

However, the above lines generate the following error:

    mt.d(54): function MAXBITS functions cannot be const or auto

would it be safe to just drop the const or is this a bug?

"Andrew Edwards" <edwardsac@spamfreeusa.com> wrote in message news:be4m35$25v$1@digitaldaemon.com...
> "Walter" <walter@digitalmars.com> wrote...
>
> > const uint MIXBITS(uint u, uint v) { return (u & UMASK) | (v & LMASK); }
> > const uint TWIST(uint u,uint v) { return (MIXBITS(u,v) >> 1) ^ (v&1 ?
> > MATRIX_A : 0); }
> >
>
> Thanks Walter,
>
> However, the above lines generate the following error:
>
>     mt.d(54): function MAXBITS functions cannot be const or auto
>
> would it be safe to just drop the const or is this a bug?

My mistake. Drop the const.

Are those functions that return a const value or const functions?

Does this type of construct tell the compiler that the function cannot have side-effects?

Sean

"Walter" <walter@digitalmars.com> wrote in message news:be4kle$ji$1@digitaldaemon.com...
> const uint MIXBITS(uint u, uint v) { return (u & UMASK) | (v & LMASK); }
> const uint TWIST(uint u,uint v) { return (MIXBITS(u,v) >> 1) ^ (v&1 ?
> MATRIX_A : 0); }

Heh.

Sean

"Walter" <walter@digitalmars.com> wrote in message news:be504p$b7s$1@digitaldaemon.com...
> > However, the above lines generate the following error:
> >
> >     mt.d(54): function MAXBITS functions cannot be const or auto
> >
> > would it be safe to just drop the const or is this a bug?
>
> My mistake. Drop the const.