public member function
Returns the least upper bound of the range of values potentially returned by member operator().
Because exponential_distribution is a right-unbounded distribution, the function returns the maximum value representable by result_type:
numeric_limits<result_type>::infinity(), depending on implementation.
The value of the least upper bound of the distribution's range that is representable with result_type.
result_type is a member type, defined as an alias of the first class template parameter (RealType).