libcruft-util/rand/mwc64x.hpp
Danny Robson f6056153e3 rename root namespace from util to cruft
This places, at long last, the core library code into the same namespace
as the extended library code.
2018-08-05 14:42:02 +10:00

36 lines
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C++

/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* Copyright 2016 Danny Robson <danny@nerdcruft.net>
*/
#ifndef __UTIL_RAND_MWC64X_HPP
#define __UTIL_RAND_MWC64X_HPP
#include <cstdint>
namespace cruft::rand {
// multiply-with-carry style generator suitable for rapid seeking and
// GPU generation.
//
// as with all such style generators, the seed value is very important.
// don't allow either half of the uint64_t to be zero.
struct mwc64x {
public:
using value_type = uint32_t;
using seed_type = uint64_t;
explicit mwc64x (seed_type);
value_type operator() (void);
private:
uint64_t m_state;
};
}
#endif