C++ named requirements: RandomNumberDistribution (since C++11)
Min standard notice:
A RandomNumberDistribution is a function object returning random numbers according to a probability density function p(x) or a discrete probability distribution P(xi).
# Notes
The parameters of a distribution object may be changed either permanently, by using d.param(p) or just for the duration of a single operator() call, by using d(g,p).
Calls to const member functions of the distribution and os « d do not affect the sequence of numbers produced by repeated d(g).