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linear_congruential::seed

Seeds the engine

void seed(UIntType x0 = default_seed);
template<class Gen>
    void seed(Gen& gen);

x0

The seed value.

Gen

The type of the seed generator.

gen

The seed generator.

The first seed function sets the stored value stored_value to 1 mod M if c mod M == 0 and x0 mod M == 0, otherwise it sets the stored value to x0 mod M. The second seed function calls seed(gen()).

 

// std_tr1__random__linear_congruential_seed.cpp 
// compile with: /EHsc 
#include <random> 
#include <iostream> 
 
typedef std::tr1::mt19937 Myeng; 
typedef std::tr1::linear_congruential<int, 16807, 0, 
    (int)((1U << 31) - 1)> Myceng;  // same as minstd_rand0 
int main() 
    { 
    Myeng eng; 
    Myceng ceng; 
    Myceng::result_type compval = ceng(); 
 
    compval = compval;  // to quiet "unused" warnings 
 
    std::cout << "A == " << Myceng::multiplier << std::endl; 
    std::cout << "C == " << Myceng::increment << std::endl; 
    std::cout << "M == " << Myceng::modulus << 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 
 
    return (0); 
    } 
 
A == 16807 C == 0 M == 2147483647 min == 1 max == 2147483646 a random value == 16807 a random value == 282475249 a random value == 1622650073

Header: <random>

Namespace: std::tr1

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