std::mersenne_twister_engine<UIntType,w,n,m,r,a,u,d,s,b,t,c,l,f>::mersenne_twister_engine

From cppreference.com

 
C++
 
Numerics library
 
Pseudo-random number generation
Uniform random bit generators
(C++20)
Engines and engine adaptors
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
Non-deterministic generator
(C++11)
Distributions
Uniform distributions
(C++11)
(C++11)
(C++11)
Bernoulli distributions
(C++11)
(C++11)
(C++11)
(C++11)
Poisson distributions
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
Normal distributions
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
(C++11)
Sampling distributions
(C++11)
(C++11)
(C++11)
Seed Sequences
(C++11)
C library
 
std::mersenne_twister_engine
 
mersenne_twister_engine() : mersenne_twister_engine(default_seed) {}
 (1) (since C++11)
explicit mersenne_twister_engine( result_type value );
 (2) (since C++11)
template< class Sseq >
explicit mersenne_twister_engine( Sseq& s );
 (3) (since C++11)
mersenne_twister_engine( const mersenne_twister_engine& );
 (4) (since C++11)
(implicitly declared)

Constructs the pseudo-random number engine.

1) Default constructor. Seeds the engine with default_seed.
2) Constructs the engine and initializes the state (n values X
i of type result_type) as follows: value mod 2w
 is used to initialize X
0 and the rest are initialized iteratively, for i=1-n,...,-1, each X
i is initialized to [f·(X
i-1xor(X
i-1rshift(w-2)))+i mod n] mod 2w
3) Constructs the engine and initializes the state by calling s.generate(a, a+n*k) where a is an array of length n*k and k is ceil(w/32) and then, iteratively for i=-n,...,-1, setting each element of the engine state X
i to (Σk-1
j=0a
k(i+n)+j}·232j
) mod 2w
, and finally if the most significant w-r bits of X
0 are zero, and if all other X
i are zero, replacing X
0 with 2w-1
.

Note: initialization requirements are based on the 2002 version of Mersenne Twister, mt19937ar.c

The overload (3) only participates in overload resolution if Sseq qualifies as a SeedSequence. In particular, it is excluded from the set of candidate functions if Sseq is convertible to result_type.

Parameters

value - seed value to use in the initialization of the internal state
s - seed sequence to use in the initialization of the internal state

Complexity

linear in n (the state size)

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

DR Applied to Behavior as published Correct behavior
P0935R0 C++11 default constructor was explicit made implicit

See also

 sets the current state of the engine
(public member function)
Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/numeric/random/mersenne_twister_engine/mersenne_twister_engine&oldid=50983"