35 lines
968 B
C++
35 lines
968 B
C++
/*
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* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/.
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*
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* Copyright 2015-2019 Danny Robson <danny@nerdcruft.net>
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*/
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#pragma once
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#include <limits>
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namespace cruft::rand {
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// implements a naive xorshift random generator.
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//
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// * users may not rely on identical output across executions or library
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// updates. internal constants may change across releases
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template <typename ValueT>
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struct xorshift {
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public:
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using result_type = ValueT;
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explicit xorshift (ValueT seed);
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result_type operator() (void);
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static constexpr result_type min (void) noexcept { return 1u; }
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static constexpr auto max (void) noexcept { return std::numeric_limits<result_type>::max (); }
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void discard (unsigned);
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private:
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ValueT m_state;
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};
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} |