FastReseededPRNG Class Reference

#include <FastReseededPRNG.h>

Collaboration diagram for FastReseededPRNG:

Public Types
using	result_type = std::uint64_t

Public Member Functions
template<typename... Int>
	FastReseededPRNG (Int... seed)
	FastReseededPRNG ()=delete
result_type	operator() ()

Static Public Member Functions
static constexpr result_type	min ()
static constexpr result_type	max ()

Private Member Functions
void	set_seed (const std::uint64_t *start, std::size_t len)
std::uint64_t	next ()

Private Attributes
std::array< std::uint64_t, 2 >	m_seed_arr

Detailed Description

Definition at line 28 of file FastReseededPRNG.h.

Member Typedef Documentation

result_type

using FastReseededPRNG::result_type = std::uint64_t

Definition at line 30 of file FastReseededPRNG.h.

Constructor & Destructor Documentation

FastReseededPRNG() [1/2]

template<typename... Int>

FastReseededPRNG::FastReseededPRNG ( Int... seed )

inline

Definition at line 32 of file FastReseededPRNG.h.

                                {
    const std::array<std::uint64_t, sizeof...(seed)> seed_array{
        static_cast<std::uint64_t>(seed)...};
    set_seed(seed_array.data(), seed_array.size());
  }

FastReseededPRNG() [2/2]

FastReseededPRNG::FastReseededPRNG ( )

delete

Member Function Documentation

max()

constexpr result_type FastReseededPRNG::max ( )

inlinestaticconstexpr

Definition at line 40 of file FastReseededPRNG.h.

                                     {
    return std::numeric_limits<std::uint64_t>::max();
  }

min()

constexpr result_type FastReseededPRNG::min ( )

inlinestaticconstexpr

Definition at line 39 of file FastReseededPRNG.h.

{ return 0; }

next()

std::uint64_t FastReseededPRNG::next ( )

private

Definition at line 46 of file FastReseededPRNG.cxx.

                                   {
  const std::uint64_t s0 = m_seed_arr[0];
  std::uint64_t s1 = m_seed_arr[1];
  const std::uint64_t result = rotl(s0 * 5, 7) * 9;
 
  s1 ^= s0;
  m_seed_arr[0] = rotl(s0, 24) ^ s1 ^ (s1 << 16);  // a, b
  m_seed_arr[1] = rotl(s1, 37);                    // c
 
  return result;
}

operator()()

FastReseededPRNG::result_type FastReseededPRNG::operator()

(

)

Definition at line 28 of file FastReseededPRNG.cxx.

                                                         {
  return next();
}

set_seed()

void FastReseededPRNG::set_seed ( const std::uint64_t * start, std::size_t len )

private

Definition at line 33 of file FastReseededPRNG.cxx.

                                                                       {
  const auto hash = XXH3_128bits(start, sizeof(std::uint64_t) * len);
  m_seed_arr[0] = hash.high64;
  m_seed_arr[1] = hash.low64;
}

Member Data Documentation

m_seed_arr

std::array<std::uint64_t, 2> FastReseededPRNG::m_seed_arr

private

Definition at line 47 of file FastReseededPRNG.h.

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The documentation for this class was generated from the following files:

• FastReseededPRNG.h
• FastReseededPRNG.cxx