59 lines
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59 lines
10 KiB
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<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="API documentation for the Rust `num_bigint` crate."><meta name="keywords" content="rust, rustlang, rust-lang, num_bigint"><title>num_bigint - Rust</title><link rel="stylesheet" type="text/css" href="../normalize.css"><link rel="stylesheet" type="text/css" href="../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../dark.css"><link rel="stylesheet" type="text/css" href="../light.css" id="themeStyle"><script src="../storage.js"></script><noscript><link rel="stylesheet" href="../noscript.css"></noscript><link rel="shortcut icon" href="../favicon.ico"><style type="text/css">#crate-search{background-image:url("../down-arrow.svg");}</style></head><body class="rustdoc mod"><!--[if lte IE 8]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu">☰</div><a href='../num_bigint/index.html'><div class='logo-container'><img src='../rust-logo.png' alt='logo'></div></a><p class='location'>Crate num_bigint</p><div class="sidebar-elems"><a id='all-types' href='all.html'><p>See all num_bigint's items</p></a><div class="block items"><ul><li><a href="#structs">Structs</a></li><li><a href="#enums">Enums</a></li><li><a href="#traits">Traits</a></li></ul></div><p class='location'></p><script>window.sidebarCurrent = {name: 'num_bigint', ty: 'mod', relpath: '../'};</script></div></nav><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!"><img src="../brush.svg" width="18" alt="Pick another theme!"></button><div id="theme-choices"></div></div><script src="../theme.js"></script><nav class="sub"><form class="search-form js-only"><div class="search-container"><div><select id="crate-search"><option value="All crates">All crates</option></select><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"></div><a id="settings-menu" href="../settings.html"><img src="../wheel.svg" width="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><h1 class='fqn'><span class='out-of-band'><span id='render-detail'><a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class='inner'>−</span>]</a></span><a class='srclink' href='../src/num_bigint/lib.rs.html#11-206' title='goto source code'>[src]</a></span><span class='in-band'>Crate <a class="mod" href=''>num_bigint</a></span></h1><div class='docblock'><p>A Big integer (signed version: <code>BigInt</code>, unsigned version: <code>BigUint</code>).</p>
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<p>A <code>BigUint</code> is represented as a vector of <code>BigDigit</code>s.
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A <code>BigInt</code> is a combination of <code>BigUint</code> and <code>Sign</code>.</p>
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<p>Common numerical operations are overloaded, so we can treat them
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the same way we treat other numbers.</p>
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<h2 id="example" class="section-header"><a href="#example">Example</a></h2>
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<div class="example-wrap"><pre class="rust rust-example-rendered">
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<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">num_bigint</span>;
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<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">num_traits</span>;
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<span class="kw">use</span> <span class="ident">num_bigint</span>::<span class="ident">BigUint</span>;
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<span class="kw">use</span> <span class="ident">num_traits</span>::{<span class="ident">Zero</span>, <span class="ident">One</span>};
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<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">mem</span>::<span class="ident">replace</span>;
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<span class="comment">// Calculate large fibonacci numbers.</span>
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<span class="kw">fn</span> <span class="ident">fib</span>(<span class="ident">n</span>: <span class="ident">usize</span>) <span class="op">-</span><span class="op">></span> <span class="ident">BigUint</span> {
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<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">f0</span>: <span class="ident">BigUint</span> <span class="op">=</span> <span class="ident">Zero</span>::<span class="ident">zero</span>();
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<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">f1</span>: <span class="ident">BigUint</span> <span class="op">=</span> <span class="ident">One</span>::<span class="ident">one</span>();
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<span class="kw">for</span> <span class="kw">_</span> <span class="kw">in</span> <span class="number">0</span>..<span class="ident">n</span> {
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<span class="kw">let</span> <span class="ident">f2</span> <span class="op">=</span> <span class="ident">f0</span> <span class="op">+</span> <span class="kw-2">&</span><span class="ident">f1</span>;
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<span class="comment">// This is a low cost way of swapping f0 with f1 and f1 with f2.</span>
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<span class="ident">f0</span> <span class="op">=</span> <span class="ident">replace</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">f1</span>, <span class="ident">f2</span>);
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}
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<span class="ident">f0</span>
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}
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<span class="comment">// This is a very large number.</span>
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<span class="macro">println</span><span class="macro">!</span>(<span class="string">"fib(1000) = {}"</span>, <span class="ident">fib</span>(<span class="number">1000</span>));</pre></div>
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<p>It's easy to generate large random numbers:</p>
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<div class="example-wrap"><pre class="rust rust-example-rendered">
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<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">rand</span>;
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<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">num_bigint</span> <span class="kw">as</span> <span class="ident">bigint</span>;
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<span class="kw">use</span> <span class="ident">bigint</span>::{<span class="ident">ToBigInt</span>, <span class="ident">RandBigInt</span>};
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<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">rng</span> <span class="op">=</span> <span class="ident">rand</span>::<span class="ident">thread_rng</span>();
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<span class="kw">let</span> <span class="ident">a</span> <span class="op">=</span> <span class="ident">rng</span>.<span class="ident">gen_bigint</span>(<span class="number">1000</span>);
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<span class="kw">let</span> <span class="ident">low</span> <span class="op">=</span> <span class="op">-</span><span class="number">10000</span>.<span class="ident">to_bigint</span>().<span class="ident">unwrap</span>();
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<span class="kw">let</span> <span class="ident">high</span> <span class="op">=</span> <span class="number">10000</span>.<span class="ident">to_bigint</span>().<span class="ident">unwrap</span>();
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<span class="kw">let</span> <span class="ident">b</span> <span class="op">=</span> <span class="ident">rng</span>.<span class="ident">gen_bigint_range</span>(<span class="kw-2">&</span><span class="ident">low</span>, <span class="kw-2">&</span><span class="ident">high</span>);
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<span class="comment">// Probably an even larger number.</span>
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<span class="macro">println</span><span class="macro">!</span>(<span class="string">"{}"</span>, <span class="ident">a</span> <span class="op">*</span> <span class="ident">b</span>);
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</pre></div>
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<h2 id="compatibility" class="section-header"><a href="#compatibility">Compatibility</a></h2>
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<p>The <code>num-bigint</code> crate is tested for rustc 1.15 and greater.</p>
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</div><h2 id='structs' class='section-header'><a href="#structs">Structs</a></h2>
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<table><tr class='module-item'><td><a class="struct" href="struct.BigInt.html" title='num_bigint::BigInt struct'>BigInt</a></td><td class='docblock-short'><p>A big signed integer type.</p>
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</td></tr><tr class='module-item'><td><a class="struct" href="struct.BigUint.html" title='num_bigint::BigUint struct'>BigUint</a></td><td class='docblock-short'><p>A big unsigned integer type.</p>
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</td></tr><tr class='module-item'><td><a class="struct" href="struct.ParseBigIntError.html" title='num_bigint::ParseBigIntError struct'>ParseBigIntError</a></td><td class='docblock-short'></td></tr></table><h2 id='enums' class='section-header'><a href="#enums">Enums</a></h2>
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<table><tr class='module-item'><td><a class="enum" href="enum.Sign.html" title='num_bigint::Sign enum'>Sign</a></td><td class='docblock-short'><p>A Sign is a <code>BigInt</code>'s composing element.</p>
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</td></tr></table><h2 id='traits' class='section-header'><a href="#traits">Traits</a></h2>
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<table><tr class='module-item'><td><a class="trait" href="trait.ToBigInt.html" title='num_bigint::ToBigInt trait'>ToBigInt</a></td><td class='docblock-short'><p>A generic trait for converting a value to a <code>BigInt</code>. This may return
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<code>None</code> when converting from <code>f32</code> or <code>f64</code>, and will always succeed
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when converting from any integer or unsigned primitive, or <code>BigUint</code>.</p>
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</td></tr><tr class='module-item'><td><a class="trait" href="trait.ToBigUint.html" title='num_bigint::ToBigUint trait'>ToBigUint</a></td><td class='docblock-short'><p>A generic trait for converting a value to a <code>BigUint</code>.</p>
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</td></tr></table></section><section id="search" class="content hidden"></section><section class="footer"></section><aside id="help" class="hidden"><div><h1 class="hidden">Help</h1><div class="shortcuts"><h2>Keyboard Shortcuts</h2><dl><dt><kbd>?</kbd></dt><dd>Show this help dialog</dd><dt><kbd>S</kbd></dt><dd>Focus the search field</dd><dt><kbd>↑</kbd></dt><dd>Move up in search results</dd><dt><kbd>↓</kbd></dt><dd>Move down in search results</dd><dt><kbd>↹</kbd></dt><dd>Switch tab</dd><dt><kbd>⏎</kbd></dt><dd>Go to active search result</dd><dt><kbd>+</kbd></dt><dd>Expand all sections</dd><dt><kbd>-</kbd></dt><dd>Collapse all sections</dd></dl></div><div class="infos"><h2>Search Tricks</h2><p>Prefix searches with a type followed by a colon (e.g., <code>fn:</code>) to restrict the search to a given type.</p><p>Accepted types are: <code>fn</code>, <code>mod</code>, <code>struct</code>, <code>enum</code>, <code>trait</code>, <code>type</code>, <code>macro</code>, and <code>const</code>.</p><p>Search functions by type signature (e.g., <code>vec -> usize</code> or <code>* -> vec</code>)</p><p>Search multiple things at once by splitting your query with comma (e.g., <code>str,u8</code> or <code>String,struct:Vec,test</code>)</p></div></div></aside><script>window.rootPath = "../";window.currentCrate = "num_bigint";</script><script src="../aliases.js"></script><script src="../main.js"></script><script defer src="../search-index.js"></script></body></html> |