std::mersenne_twister_engine<UIntType,w,n,m,r,a,u,d,s,b,t,c,l,f>::mersenne_twister_engine (3) - Linux Man Pages

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

NAME

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

Synopsis


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 > (3) (since C++11)
explicit mersenne_twister_engine( Sseq& s );
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
seed (public member function)