cpp/experimental/ranges/concepts/UniformRandomNumberGenerator

The concept specifies that  is the type of a uniform random number generator, that is, objects of type  is a function object returning unsigned integer values such that each value in the range of possible results has (ideally) equal probability of being returned.

is satisfied only if, given any object of type :
 * and are prvalue constant expressions;
 * is in the range
 * has amortized constant complexity.
 * has amortized constant complexity.