__gnu_cxx:...active_rng(3)

📦

version 16.2.1+r23+gd564253eb6c8 · 6 versions

16.2.1+r23+gd564253eb6c8 · arch rolling, centos-stream 10, fedora 43, fedora 44 (latest)
16.2.1 · centos-stream 9
14.2.1 · centos-stream 9
13.3.1 · centos-stream 9
12.2.1 · centos-stream 9
4.4.0 · nixpkgs unstable

, in arch rolling, centos-stream 10, fedora 43, fedora 44

🌸 NAME 🌸

__gnu_cxx::subtractive_rng — bestie, it's a random number generator class, and we're gonna learn her together 💖

✨ SYNOPSIS ✨

#include <functional>

She inherits from std::unary_function< unsigned int, unsigned int >, which is giving legacy-but-iconic energy 🎀

💅 Public Types

typedef unsigned int argument_type — argument_type is the type of the argument. that's literally her whole job, no notes 🫶
typedef unsigned int result_type — result_type is the return type. same deal, she tells you what comes back out 🌈

👑 Public Member Functions

subtractive_rng () — the default ctor; initializes its state with some number you don't see 🙈 (mysterious! we love a secret)
subtractive_rng (unsigned int __seed) — the ctor that actually lets you initialize the seed, so you're in control, main character energy ⭐
void _M_initialize (unsigned int __seed) — internal init helper, lowkey doing the heavy lifting behind the scenes 🧚
unsigned int operator() (unsigned int __limit) — returns a number less than the argument. yes, that's the call operator, she's callable, she's a whole vibe 💅

📖 Detailed Description 📖

The subtractive_rng class is documented on SGI's site, so if you want the deep lore, that's where it lives 🔥

Note that this code assumes that int is 32 bits. fr fr, don't come for her on exotic platforms, she said what she said 💀

🎀 Member Typedef Documentation 🎀

`typedef unsigned int std::unary_function< unsigned int, unsigned int >::argument_type` [inherited]

argument_type is the type of the argument. inherited, so she got it from the family 💜

`typedef unsigned int std::unary_function< unsigned int, unsigned int >::result_type` [inherited]

result_type is the return type. also inherited, also iconic 🌸

🦋 Constructor & Destructor Documentation 🦋

`__gnu_cxx::subtractive_rng::subtractive_rng (unsigned int __seed)` [inline]

Ctor allowing you to initialize the seed. you pick the number, you set the vibe ✨

`__gnu_cxx::subtractive_rng::subtractive_rng ()` [inline]

Default ctor; initializes its state with some number you don't see. it's giving mystery, it's giving trust the process 🙈

💖 Member Function Documentation 💖

`unsigned int __gnu_cxx::subtractive_rng::operator() (unsigned int __limit)` [inline]

Returns a number less than the argument. so you hand her a __limit, she hands you back something smaller. that's it, that's the whole relationship 💅

🌟 Author 🌟

Generated automatically by Doxygen for libstdc++ from the source code. not a human author, just a robot doing her little documentation dance 🤖💫

and that's the whole page, bestie 🫶 this one came out of libstdc++, page __gnu_cxx:...active_rng(3) from the Library Functions Manual, section 3 — go forth and generate numbers responsibly, ily, bye 💖✨🎀

📦 where this page comes from

arch rolling: gcc 16.2.1+r23+gd564253eb6c8-1 · GPL-3.0-or-later WITH GCC-exception-3.1 AND GFDL-1.3-or-later
centos-stream 10: gcc-toolset-15-libstdc++-docs 15.2.1-8.1.el10 · GPL-3.0-or-later AND LGPL-3.0-or-later AND (GPL-3.0-or-later WITH GCC-exception-3.1) AND (GPL-3.0-or-later WITH Texinfo-exception) AND (LGPL-2.1-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GNU-compiler-exception) AND BSL-1.0 AND GFDL-1.3-or-later AND Linux-man-pages-copyleft-2-para AND SunPro AND BSD-1-Clause AND BSD-2-Clause AND BSD-2-Clause-Views AND BSD-3-Clause AND BSD-4-Clause AND BSD-Source-Code AND Zlib AND MIT AND Apache-2.0 AND (Apache-2.0 WITH LLVM-Exception) AND ZPL-2.1 AND ISC AND LicenseRef-Fedora-Public-Domain AND HP-1986 AND curl AND Martin-Birgmeier AND HPND-Markus-Kuhn AND dtoa AND SMLNJ AND AMD-newlib AND OAR AND HPND-merchantability-variant AND HPND-Intel
centos-stream 10: gcc-toolset-16-libstdc++-docs 16.2.1-1.3.el10 · GPL-3.0-or-later AND LGPL-3.0-or-later AND (GPL-3.0-or-later WITH GCC-exception-3.1) AND (GPL-3.0-or-later WITH Texinfo-exception) AND (LGPL-2.1-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GNU-compiler-exception) AND BSL-1.0 AND GFDL-1.3-or-later AND Linux-man-pages-copyleft-2-para AND SunPro AND BSD-1-Clause AND BSD-2-Clause AND BSD-2-Clause-Views AND BSD-3-Clause AND BSD-4-Clause AND BSD-Source-Code AND Zlib AND MIT AND Apache-2.0 AND (Apache-2.0 WITH LLVM-Exception) AND ZPL-2.1 AND ISC AND LicenseRef-Fedora-Public-Domain AND HP-1986 AND curl AND Martin-Birgmeier AND HPND-Markus-Kuhn AND dtoa AND SMLNJ AND AMD-newlib AND OAR AND HPND-merchantability-variant AND HPND-Intel
centos-stream 10: libstdc++-docs 14.4.1-4.el10 · GPL-3.0-or-later AND LGPL-3.0-or-later AND (GPL-3.0-or-later WITH GCC-exception-3.1) AND (GPL-3.0-or-later WITH Texinfo-exception) AND (LGPL-2.1-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GNU-compiler-exception) AND BSL-1.0 AND GFDL-1.3-or-later AND Linux-man-pages-copyleft-2-para AND SunPro AND BSD-1-Clause AND BSD-2-Clause AND BSD-2-Clause-Views AND BSD-3-Clause AND BSD-4-Clause AND BSD-Source-Code AND Zlib AND MIT AND Apache-2.0 AND (Apache-2.0 WITH LLVM-Exception) AND ZPL-2.1 AND ISC AND LicenseRef-Fedora-Public-Domain AND HP-1986 AND curl AND Martin-Birgmeier AND HPND-Markus-Kuhn AND dtoa AND SMLNJ AND AMD-newlib AND OAR AND HPND-merchantability-variant AND HPND-Intel
fedora 43: libstdc++-docs 15.2.1-2.fc43 · GPL-3.0-or-later AND LGPL-3.0-or-later AND (GPL-3.0-or-later WITH GCC-exception-3.1) AND (GPL-3.0-or-later WITH Texinfo-exception) AND (LGPL-2.1-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GNU-compiler-exception) AND BSL-1.0 AND GFDL-1.3-or-later AND Linux-man-pages-copyleft-2-para AND SunPro AND BSD-1-Clause AND BSD-2-Clause AND BSD-2-Clause-Views AND BSD-3-Clause AND BSD-4-Clause AND BSD-Source-Code AND Zlib AND MIT AND Apache-2.0 AND (Apache-2.0 WITH LLVM-Exception) AND ZPL-2.1 AND ISC AND LicenseRef-Fedora-Public-Domain AND HP-1986 AND curl AND Martin-Birgmeier AND HPND-Markus-Kuhn AND dtoa AND SMLNJ AND AMD-newlib AND OAR AND HPND-merchantability-variant AND HPND-Intel
fedora 43: libstdc++-docs 15.3.1-1.fc43 · GPL-3.0-or-later AND LGPL-3.0-or-later AND (GPL-3.0-or-later WITH GCC-exception-3.1) AND (GPL-3.0-or-later WITH Texinfo-exception) AND (LGPL-2.1-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GNU-compiler-exception) AND BSL-1.0 AND GFDL-1.3-or-later AND Linux-man-pages-copyleft-2-para AND SunPro AND BSD-1-Clause AND BSD-2-Clause AND BSD-2-Clause-Views AND BSD-3-Clause AND BSD-4-Clause AND BSD-Source-Code AND Zlib AND MIT AND Apache-2.0 AND (Apache-2.0 WITH LLVM-Exception) AND ZPL-2.1 AND ISC AND LicenseRef-Fedora-Public-Domain AND HP-1986 AND curl AND Martin-Birgmeier AND HPND-Markus-Kuhn AND dtoa AND SMLNJ AND AMD-newlib AND OAR AND HPND-merchantability-variant AND HPND-Intel
fedora 44: libstdc++-docs 16.0.1-0.10.fc44 · GPL-3.0-or-later AND LGPL-3.0-or-later AND (GPL-3.0-or-later WITH GCC-exception-3.1) AND (GPL-3.0-or-later WITH Texinfo-exception) AND (LGPL-2.1-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GNU-compiler-exception) AND BSL-1.0 AND GFDL-1.3-or-later AND Linux-man-pages-copyleft-2-para AND SunPro AND BSD-1-Clause AND BSD-2-Clause AND BSD-2-Clause-Views AND BSD-3-Clause AND BSD-4-Clause AND BSD-Source-Code AND Zlib AND MIT AND Apache-2.0 AND (Apache-2.0 WITH LLVM-Exception) AND ZPL-2.1 AND ISC AND LicenseRef-Fedora-Public-Domain AND HP-1986 AND curl AND Martin-Birgmeier AND HPND-Markus-Kuhn AND dtoa AND SMLNJ AND AMD-newlib AND OAR AND HPND-merchantability-variant AND HPND-Intel
fedora 44: libstdc++-docs 16.2.1-2.fc44
fedora 44: libstdc++-docs 16.2.1-3.fc44 · GPL-3.0-or-later AND LGPL-3.0-or-later AND (GPL-3.0-or-later WITH GCC-exception-3.1) AND (GPL-3.0-or-later WITH Texinfo-exception) AND (LGPL-2.1-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GCC-exception-2.0) AND (GPL-2.0-or-later WITH GNU-compiler-exception) AND BSL-1.0 AND GFDL-1.3-or-later AND Linux-man-pages-copyleft-2-para AND SunPro AND BSD-1-Clause AND BSD-2-Clause AND BSD-2-Clause-Views AND BSD-3-Clause AND BSD-4-Clause AND BSD-Source-Code AND Zlib AND MIT AND Apache-2.0 AND (Apache-2.0 WITH LLVM-Exception) AND ZPL-2.1 AND ISC AND LicenseRef-Fedora-Public-Domain AND HP-1986 AND curl AND Martin-Birgmeier AND HPND-Markus-Kuhn AND dtoa AND SMLNJ AND AMD-newlib AND OAR AND HPND-merchantability-variant AND HPND-Intel
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on 2026-10-14: a language model's rewrite of the original, under its terms