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M.E. O'Neill imneme

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imneme / randutils.hpp
Last active February 7, 2026 14:45
Addresses common issues with C++11 random number generation; makes good seeding easier, and makes using RNGs easy while retaining all the power.
/*
* Random-Number Utilities (randutil)
* Addresses common issues with C++11 random number generation.
* Makes good seeding easier, and makes using RNGs easy while retaining
* all the power.
*
* The MIT License (MIT)
*
* Copyright (c) 2015-2022 Melissa E. O'Neill
*
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imneme / narrowing_cast.hpp
Created October 11, 2025 00:11
Safe numeric conversions for C++ — comprehensive `narrowing_cast` that throws on overflow, with handy shorthands like `to_int`.
/*
* Safe numeric casts for C++.
*
* - Provides a function template `narrowing_cast<To>(From value)` that safely
* converts from one numeric type to another, throwing std::overflow_error
* if the value cannot be represented in the target type.
*
* - Also provides convenience functions like `to_int16_t(value)`,
* `to_int32_t(value)`, and `to_int64_t(value)` for common conversions.
*
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imneme / splitmix.hpp
Last active June 9, 2025 21:39
A C++ implementation of SplitMix
#ifndef SPLITMIX_HPP_INCLUDED
#define SPLITMIX_HPP_INCLUDED 1
/*
* A C++ implementation of SplitMix
* Original design by Guy L. Steele, Jr., Doug Lea and Christine H. Flood
* Described in _Fast splittable pseudorandom number generators_
* http://dx.doi.org/10.1145/2714064.2660195 and implemented in
* Java 8 as SplittableRandom
* Based on code from the original paper, with revisions based on changes
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imneme / chacha.hpp
Last active January 27, 2025 19:56 — forked from orlp/chacha.h
C++11 ChaCha implementation.
#ifndef CHACHA_HPP_INCLUDED
#define CHACHA_HPP_INCLUDED 1
/*
* A C++ version of ChaCha PRNG (*modified* from Orson Peters original code)
*
* Changes Copyright (c) 2017-18 Melissa E. O'Neill, licence as below.
*
* Changes compared to original 2015 version:
* - Some formatting fixes
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imneme / sfc.hpp
Last active July 6, 2024 10:23
A C++ implementation of Chris Doty-Humphrey's SFC PRNG(s)
#ifndef SFC_HPP_INCLUDED
#define SFC_HPP_INCLUDED 1
/*
* A C++ implementation of Chris Doty-Humphrey's SFC PRNG(s)
*
* The MIT License (MIT)
*
* Copyright (c) 2018 Melissa E. O'Neill
*
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imneme / xorshift.hpp
Last active February 15, 2023 17:47
A Family of Truncated XorShift* PRNGs
#ifndef XORSHIFT_HPP_INCLUDED
#define XORSHIFT_HPP_INCLUDED 1
/*
* A C++ implementation of a family of truncated XorShift* generators.
*
* The MIT License (MIT)
*
* Copyright (c) 2017-19 Melissa E. O'Neill
*
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imneme / jsf.hpp
Created May 28, 2018 02:40
A C++ Implementation of Bob Jenkins's Small Fast Noncryptographic PRNG (JSF)
#ifndef JSF_HPP_INCLUDED
#define JSF_HPP_INCLUDED 1
/*
* A C++ implementation of a Bob Jenkins Small Fast (Noncryptographic) PRNGs
*
* The MIT License (MIT)
*
* Copyright (c) 2018 Melissa E. O'Neill
*
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imneme / lehmer.hpp
Created June 9, 2018 20:39
A C++ implementation of 128-bit Lehmer-style PRNGs
#ifndef LEHMER_HPP_INCLUDED
#define LEHMER_HPP_INCLUDED 1
/*
* A C++ implementation of fast, 128-bit, Lehmer-style PRNGs
*
* The MIT License (MIT)
*
* Copyright (c) 2018 Melissa E. O'Neill
*
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imneme / gjrand.hpp
Created May 28, 2018 07:45
A C++ implementation of David Blackman's GJrand PRNG(s)
#ifndef GJRAND_HPP_INCLUDED
#define GJRAND_HPP_INCLUDED 1
/*
* A C++ implementation of David Blackman's GJrand PRNG(s)
*
* The MIT License (MIT)
*
* Copyright (c) 2018 Melissa E. O'Neill
*
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imneme / xoshiro.hpp
Created July 4, 2018 04:23
A C++ implementation of a family of Xoshiro generators
#ifndef XOSHIRO_HPP_INCLUDED
#define XOSHIRO_HPP_INCLUDED 1
/*
* A C++ implementation of a family of Xoshiro generators.
*
* See:
* https://arxiv.org/abs/1805.01407
* http://xoshiro.di.unimi.it/xoshiro256plus.c
* http://xoshiro.di.unimi.it/xoshiro256starstar.c