54 lines
1.6 KiB
Markdown
54 lines
1.6 KiB
Markdown
[c.math.rand]
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# 29 Numerics library [[numerics]](./#numerics)
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## 29.5 Random number generation [[rand]](rand#c.math.rand)
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### 29.5.10 Low-quality random number generation [c.math.rand]
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[1](#1)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L6923)
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[*Note [1](#note-1)*:
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The header [<cstdlib>](cstdlib.syn#header:%3ccstdlib%3e "17.2.2 Header <cstdlib> synopsis [cstdlib.syn]") declares the functions described in this subclause[.](#1.sentence-1)
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â *end note*]
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[ð](#lib:rand)
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`int rand();
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void srand(unsigned int seed);
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`
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[2](#2)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L6937)
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*Effects*: Therand and srand functions have the semantics specified in the C standard library[.](#2.sentence-1)
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[3](#3)
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[#](http://github.com/Eelis/draft/tree/9adde4bc1c62ec234483e63ea3b70a59724c745a/source/numerics.tex#L6943)
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*Remarks*: The implementation
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may specify that particular library functions may callrand[.](#3.sentence-1)
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It is implementation-defined
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whether the rand function
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may introduce data races ([[res.on.data.races]](res.on.data.races "16.4.6.10 Data race avoidance"))[.](#3.sentence-2)
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[*Note [2](#note-2)*:
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The other random
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number generation facilities in this document ([[rand]](rand "29.5 Random number generation")) are often preferable
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to rand, because rand's underlying algorithm is unspecified[.](#3.sentence-3)
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Use of rand therefore continues to be non-portable, with unpredictable
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and oft-questionable quality and performance[.](#3.sentence-4)
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â *end note*]
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See also: ISO/IEC 9899:2024, 7.22.2
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