Sha256: ef9fb18e8a808af0ef3d7dfd37d3436ec6c97a5ed5db80fc37da2ea3db529840
Contents?: true
Size: 1.57 KB
Versions: 16
Compression:
Stored size: 1.57 KB
Contents
#ifndef _IV_XORSHIFT_H_
#define _IV_XORSHIFT_H_
#include <ctime>
#include <tr1/cstdint>
#include <tr1/random>
namespace iv {
namespace core {
class Xor128 {
public:
typedef std::tr1::uint32_t result_type;
Xor128()
: x_(123456789),
y_(362436069),
z_(521266629),
w_(88675123) {
seed();
}
explicit Xor128(result_type x0)
: x_(123456789),
y_(362436069),
z_(521266629),
w_(88675123) {
seed(x0);
}
static result_type min() {
return limits::min();
}
static result_type max() {
return limits::max();
}
void seed() {
seed(static_cast<result_type>(std::time(NULL)));
}
void seed(result_type x0) {
x_ ^= x0;
y_ ^= RotateLeft<17>(x0);
z_ ^= RotateLeft<31>(x0);
w_ ^= RotateLeft<18>(x0);
}
void discard(unsigned long long count) { // NOLINT
for (unsigned long long i = 0; i < count; ++i) { // NOLINT
(*this)();
}
}
result_type operator()() {
const int_t t = x_ ^ (x_ << 11);
x_ = y_;
y_ = z_;
z_ = w_;
w_ = (w_ ^ (w_ >> 19)) ^ (t ^ (t >> 8));
return w_;
}
private:
typedef std::tr1::uint32_t int_t;
typedef std::numeric_limits<result_type> limits;
static const std::size_t kIntBits =
limits::digits + (limits::is_signed ? 1 : 0);
static const result_type kMask= limits::digits + (limits::is_signed ? 1 : 0);
template<std::size_t N>
static inline result_type RotateLeft(result_type x) {
return (x << N) | (x >> (kIntBits - N));
}
int_t x_;
int_t y_;
int_t z_;
int_t w_;
};
} } // namespace iv::core
#endif // _IV_XORSHIFT_H_
Version data entries
16 entries across 16 versions & 1 rubygems