subtract_with_carry::seed

Seeds the engine.

void seed(result_type x0 = 19780503UL);
template<class Gen>
    void seed(Gen& gen);

Parameters

• Gen
  The type of the seed generator.

• gen
  The seed generator.

• x0
  The seed value.

Remarks

Precondition: 0 < x0

The first seed function generates long_lag historical values from the values of type unsigned long returned by successive invocations of gen. Each historical value is gen() % modulus.

The second seed function effectively executes the following code:

    linear_congruential<unsigned long, 40014, 0, 2147483563> gen(x0);
    seed(gen);

Example

// std_tr1__random__subtract_with_carry_seed.cpp 
// compile with: /EHsc 
#include <random> 
#include <iostream> 
 
typedef std::mt19937 Myeng; 
typedef std::subtract_with_carry<unsigned int, 1 << 24, 
    10, 24> Myceng; 
int main() 
    { 
    Myeng eng; 
    Myceng ceng; 
    Myceng::result_type compval = ceng(); 
 
    compval = compval;  // to quiet "unused" warnings 
 
    std::cout << "M == " << Myceng::modulus << std::endl; 
    std::cout << "S == " << Myceng::short_lag << std::endl; 
    std::cout << "R == " << Myceng::long_lag << std::endl; 
 
    std::cout << "min == " << ceng.min() << std::endl; 
    std::cout << "max == " << ceng.max() << std::endl; 
 
    ceng.seed(); // reseed base engine 
    std::cout << "a random value == " << ceng() << std::endl; 
    std::cout << "a random value == " << ceng() << std::endl; 
    std::cout << "a random value == " << ceng() << std::endl; 
 
    Myceng ceng2(eng); // construct with generator 
    ceng2.seed(eng);  // seed with generator 
 
    Myceng ceng3(5UL);  // construct with unsigned long seed 
    ceng3.seed(5UL);  // seed with unsigned long 
 
    return (0); 
    } 
 

M == 16777216
S == 10
R == 24
min == 0
max == 16777215
a random value == 15039276
a random value == 16323925
a random value == 14283486

Requirements

Header: <random>

Namespace: std

See Also

Reference

<random>

subtract_with_carry Class

Other Resources

<random> Members