问Stl: exponential_distribution -使用最小值和最大值作为输入参数

EN

template <typename RealType>
struct my_distribution
{
    struct param_type : typename std::exponential_distribution<RealType>::param_type
    {
        RealType min;
        RealType max;
    };

    using result_type = RealType

    my_distribution(RealType lambda, RealType min, RealType max) : m_exp(lambda), m_param(lambda, min, max) {}
    my_distribution(param_type param) : m_exp(param), m_param(param) {}

    template <typename URBG>
    result_type operator()(URBG & gen)
    {
        result_type initial = m_exp(gen);
        // some calculation of value here involving m_param.min, m_param.max
        return value;
    }

    template <typename URBG>
    result_type operator()(URBG & gen, const param_type & param)
    {
        result_type initial = m_exp(gen, param);
        // some calculation of value here involving param.min, param.max
        return value;
    }

    param_type param() { return m_param; }
    void param(const param_type & param) { m_exp.param(param); m_param = param; }

    result_type lambda() { return m_exp.lambda(); }
    result_type min() { return m_param.min; }
    result_type max() { return m_param.max; }
private:
    std::exponential_distribution<RealType> m_exp;
    param_type m_param;
}