26 Numerics library [numerics]

26.5 Random number generation [rand]

26.5.8 Random number distribution class templates [rand.dist] Bernoulli distributions [rand.dist.bern] Class template geometric_distribution [rand.dist.bern.geo]

A geometric_distribution random number distribution produces integer values i ≥ 0 distributed according to the discrete probability function P(i | p) = p · (1-p)i .

template<class IntType = int>
 class geometric_distribution{
 // types
 typedef IntType result_type;
 typedef unspecified param_type;

 // constructors and reset functions
 explicit geometric_distribution(double p = 0.5);
 explicit geometric_distribution(const param_type& parm);
 void reset();

 // generating functions
 template<class URNG>
   result_type operator()(URNG& g);
 template<class URNG>
   result_type operator()(URNG& g, const param_type& parm);

 // property functions
 double p() const;
 param_type param() const;
 void param(const param_type& parm);
 result_type min() const;
 result_type max() const;

explicit geometric_distribution(double p = 0.5);

Requires: 0 < p < 1.

Effects: Constructs a geometric_distribution object; p corresponds to the parameter of the distribution.

double p() const;

Returns: The value of the p parameter with which the object was constructed.