random_device::entropy

估计数据源的随机性。

double entropy() const;

备注

成员函数在位返回数据源的随机性的估计，如度量。(非常，非源具有随机平均信息量零。)

示例

// std_tr1__random__random_device_entropy.cpp 
// compile with: /EHsc 
#include <random> 
#include <iostream> 
 
typedef std::random_device Myceng; 
int main() 
    { 
    Myceng ceng; 
    Myceng::result_type compval = ceng(); 
 
    compval = compval;  // to quiet "unused" warnings 
 
    std::cout << "entropy == " << ceng.entropy() << std::endl; 
    std::cout << "min == " << ceng.min() << std::endl; 
    std::cout << "max == " << ceng.max() << std::endl; 
 
    std::cout << "a random value == " << ceng() << std::endl; 
    std::cout << "a random value == " << ceng() << std::endl; 
    std::cout << "a random value == " << ceng() << std::endl; 
 
    return (0); 
    } 
 

要求

标头: <random>

命名空间: std

请参见

参考

<random>

random_device Class