1st draft of complete class-based std.random successor

[Joseph Rushton Wakeling]

On Thursday, 20 March 2014 at 00:09:51 UTC, bearophile wrote:
> Do you have a simple but very fast function that generates 
> uniforms in [0.0, 1.0]? :-)

No, but it's planned.  Jerro wrote quite a nice one in the course 
of his work on the Ziggurat algorithm, and I'm sure he'd be happy 
for me to adapt it accordingly.