dxorshift: random number generators from the extended Xorshift family

[Joseph Rushton Wakeling via Digitalmars-d-announce]

On Sunday, 15 May 2016 at 14:25:44 UTC, Basile B. wrote:
> The wrapper could be smaller with an alias this:
>
> [... snip ...]
>
> even if I'm not 100% sure if this is conform with previous 
> version. At least the tests pass.

I'm surprised that one passes the test,

    static assert(!isForwardRange!SafeRNG);

... ?  Or did you only try the tests applied to the dxorshift 
generators?

More generally: what I'd be worried about with this version is 
that it readily re-opens the door to accidentally copying the 
underlying RNG by value, if (as with Phobos RNGs) the postblit is 
not disabled.

The wrapper I provided is more verbose, but it should guarantee 
statistical safety in that respect.

I also have a personal bugbear about `alias this` inasmuch as the 
current permissions constraints _force_ the exposure of 
implementation details (i.e. the `getGen` method has to be 
public), but that's more of a frustration than a serious worry in 
this case ;-)