public member function
<random>
| (1) | explicit subtract_with_carry_engine ( result_type val = default_seed ); |
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| (2) | template <class Sseq>explicit subtract_with_carry_engine ( Sseq& q ); |
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Construct subtract-with-carry engine
Parameters
- val
- A seeding value. An entire state sequence is generated from this value using a linear_congruential_engine object.
result_type is a member type, defined as an alias of the first class template parameter (UIntType).
default_seed is a member constant, defined as 5489u.
- q
- A seed sequence object, such as an object of type seed_seq.
Sseq shall be a seed sequence class, with a generate member function.
Example
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// subtract_with_carry_engine example
#include <iostream>
#include <chrono>
#include <random>
int main ()
{
typedef std::chrono::high_resolution_clock myclock;
myclock::time_point beginning = myclock::now();
// obtain a seed from a user string:
std::string str;
std::cout << "Please, enter a seed: ";
std::getline(std::cin,str);
std::seed_seq seed1 (str.begin(),str.end());
// obtain a seed from the timer
myclock::duration d = myclock::now() - beginning;
unsigned seed2 = d.count();
std::subtract_with_carry_engine<unsigned,24,10,24> g1 (seed1);
std::cout << "Your seed produced: " << g1() << std::endl;
std::subtract_with_carry_engine<unsigned,24,10,24> g2 (seed2);
std::cout << "A time seed produced: " << g2() << std::endl;
return 0;
}
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Possible output:
Please, enter a seed: Marsaglia
A time seed produced: 15090552
Your seed produced: 3371356
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Complexity
Linear on long_lag.