Synopsis

template<class RealType = double>
    class exponential_distribution {
public:
    typedef RealType input_type;
    typedef RealType result_type;
    explicit exponential_distribution(const result_type& lambda0 = result_type(1));
    result_type lambda() const;
    void reset();
    template<class Engine>
        result_type operator()(Engine& eng);
private:
    result_type stored_lambda;   // exposition only
    };