libcruft-util/rand/xorshift.hpp

/*
 * 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 2015-2016 Danny Robson <danny@nerdcruft.net>
 */

#ifndef __UTIL_RAND_XORSHIFT_HPP
#define __UTIL_RAND_XORSHIFT_HPP

namespace cruft::rand {
    // implements a naive xorshift random generator.
    //
    // * does not comply with the c++11 rng class requirements
    // * users may not rely on identical output across executions or library
    //   updates. internal constants may change across releases
    template <typename T>
    struct xorshift {
    public:
        using result_type = T;

        explicit xorshift (T seed);

        result_type operator() (void);

        static result_type min (void);
        static result_type max (void);

        void discard (unsigned);

    private:
        T m_state;
    };
}

#endif