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subtract_with_carry::seed

Seeds the engine.

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

Gen

The type of the seed generator.

gen

The seed generator.

x0

The seed value.

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);

 

// std_tr1__random__subtract_with_carry_seed.cpp 
// compile with: /EHsc 
#include <random> 
#include <iostream> 
 
typedef std::tr1::mt19937 Myeng; 
typedef std::tr1::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

Header: <random>

Namespace: std::tr1

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