returns a single value with the probability distribution of the current Ziggurat
and slightly worse randomness (in the normal case uses only 32 random bits).
Cannot be 0.
structZiggurat(RandG, T, alias probDensityF, alias tailGenerator, bool hasNegative = true)
returns a single value with the probability distribution of the current Ziggurat and slightly worse randomness (in the normal case uses only 32 random bits). Cannot be 0.