Constructs the distribution.
explicit geometric_distribution(RealType p = 0.5); explicit geometric_distribution(const param_type& parm);
Precondition: 0.0 < p && p < 1.0
The first constructor constructs an object whose stored p value holds the value p.
The second constructor constructs an object whose stored parameters are initialized from parm. You can obtain and set the current parameters of an existing distribution by calling the param() member function.