<!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 `Octal` trait in crate `core`."> <meta name="keywords" content="rust, rustlang, rust-lang, Octal"> <title>core::fmt::Octal - 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="../../main.css" id="themeStyle"> <script src="../../storage.js"></script> <link rel="shortcut icon" href="https://doc.rust-lang.org/favicon.ico"> </head> <body class="rustdoc trait"> <!--[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='../../core/index.html'><img src='https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png' alt='logo' width='100'></a> <p class='location'>Trait Octal</p><div class="sidebar-elems"><div class="block items"><a class="sidebar-title" href="#required-methods">Required Methods</a><div class="sidebar-links"><a href="#tymethod.fmt">fmt</a></div><a class="sidebar-title" href="#implementors">Implementors</a></div><p class='location'><a href='../index.html'>core</a>::<wbr><a href='index.html'>fmt</a></p><script>window.sidebarCurrent = {name: 'Octal', ty: 'trait', relpath: ''};</script><script defer src="sidebar-items.js"></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"> <input class="search-input" name="search" autocomplete="off" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"> </div> </form> </nav> <section id='main' class="content"> <h1 class='fqn'><span class='in-band'>Trait <a href='../index.html'>core</a>::<wbr><a href='index.html'>fmt</a>::<wbr><a class="trait" href=''>Octal</a></span><span class='out-of-band'><span class='since' title='Stable since Rust version 1.0.0'>1.0.0</span><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/core/fmt/mod.rs.html#677-681' title='goto source code'>[src]</a></span></h1> <pre class='rust trait'>pub trait Octal { fn <a href='#tymethod.fmt' class='fnname'>fmt</a>(&self, f: &mut <a class="struct" href="../../core/fmt/struct.Formatter.html" title="struct core::fmt::Formatter">Formatter</a>) -> <a class="type" href="../../core/fmt/type.Result.html" title="type core::fmt::Result">Result</a>; }</pre><div class='docblock'><p><code>o</code> formatting.</p> <p>The <code>Octal</code> trait should format its output as a number in base-8.</p> <p>For primitive signed integers (<code>i8</code> to <code>i128</code>, and <code>isize</code>), negative values are formatted as the two’s complement representation.</p> <p>The alternate flag, <code>#</code>, adds a <code>0o</code> in front of the output.</p> <p>For more information on formatters, see <a href="../../std/fmt/index.html">the module-level documentation</a>.</p> <h1 id="examples" class="section-header"><a href="#examples">Examples</a></h1> <p>Basic usage with <code>i32</code>:</p> <pre class="rust rust-example-rendered"> <span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="number">42</span>; <span class="comment">// 42 is '52' in octal</span> <span class="macro">assert_eq</span><span class="macro">!</span>(<span class="macro">format</span><span class="macro">!</span>(<span class="string">"{:o}"</span>, <span class="ident">x</span>), <span class="string">"52"</span>); <span class="macro">assert_eq</span><span class="macro">!</span>(<span class="macro">format</span><span class="macro">!</span>(<span class="string">"{:#o}"</span>, <span class="ident">x</span>), <span class="string">"0o52"</span>); <span class="macro">assert_eq</span><span class="macro">!</span>(<span class="macro">format</span><span class="macro">!</span>(<span class="string">"{:o}"</span>, <span class="op">-</span><span class="number">16</span>), <span class="string">"37777777760"</span>);<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=%23!%5Ballow(unused)%5D%0Afn%20main()%20%7B%0Alet%20x%20%3D%2042%3B%20%2F%2F%2042%20is%20'52'%20in%20octal%0A%0Aassert_eq!(format!(%22%7B%3Ao%7D%22%2C%20x)%2C%20%2252%22)%3B%0Aassert_eq!(format!(%22%7B%3A%23o%7D%22%2C%20x)%2C%20%220o52%22)%3B%0A%0Aassert_eq!(format!(%22%7B%3Ao%7D%22%2C%20-16)%2C%20%2237777777760%22)%3B%0A%7D">Run</a></pre> <p>Implementing <code>Octal</code> on a type:</p> <pre class="rust rust-example-rendered"> <span class="kw">use</span> <span class="ident">std</span>::<span class="ident">fmt</span>; <span class="kw">struct</span> <span class="ident">Length</span>(<span class="ident">i32</span>); <span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Octal</span> <span class="kw">for</span> <span class="ident">Length</span> { <span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> { <span class="kw">let</span> <span class="ident">val</span> <span class="op">=</span> <span class="self">self</span>.<span class="number">0</span>; <span class="macro">write</span><span class="macro">!</span>(<span class="ident">f</span>, <span class="string">"{:o}"</span>, <span class="ident">val</span>) <span class="comment">// delegate to i32's implementation</span> } } <span class="kw">let</span> <span class="ident">l</span> <span class="op">=</span> <span class="ident">Length</span>(<span class="number">9</span>); <span class="macro">println</span><span class="macro">!</span>(<span class="string">"l as octal is: {:o}"</span>, <span class="ident">l</span>);<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=%23!%5Ballow(unused)%5D%0Afn%20main()%20%7B%0Ause%20std%3A%3Afmt%3B%0A%0Astruct%20Length(i32)%3B%0A%0Aimpl%20fmt%3A%3AOctal%20for%20Length%20%7B%0A%20%20%20%20fn%20fmt(%26self%2C%20f%3A%20%26mut%20fmt%3A%3AFormatter)%20-%3E%20fmt%3A%3AResult%20%7B%0A%20%20%20%20%20%20%20%20let%20val%20%3D%20self.0%3B%0A%0A%20%20%20%20%20%20%20%20write!(f%2C%20%22%7B%3Ao%7D%22%2C%20val)%20%2F%2F%20delegate%20to%20i32's%20implementation%0A%20%20%20%20%7D%0A%7D%0A%0Alet%20l%20%3D%20Length(9)%3B%0A%0Aprintln!(%22l%20as%20octal%20is%3A%20%7B%3Ao%7D%22%2C%20l)%3B%0A%7D">Run</a></pre> </div> <h2 id='required-methods' class='small-section-header'> Required Methods<a href='#required-methods' class='anchor'></a> </h2> <div class='methods'> <h3 id='tymethod.fmt' class='method'><span id='fmt.v' class='invisible'><code>fn <a href='#tymethod.fmt' class='fnname'>fmt</a>(&self, f: &mut <a class="struct" href="../../core/fmt/struct.Formatter.html" title="struct core::fmt::Formatter">Formatter</a>) -> <a class="type" href="../../core/fmt/type.Result.html" title="type core::fmt::Result">Result</a></code></span></h3><div class='docblock'><p>Formats the value using the given formatter.</p> </div></div> <h2 id='implementors' class='small-section-header'> Implementors<a href='#implementors' class='anchor'></a> </h2> <ul class='item-list' id='implementors-list'> <li><div class='out-of-band'><a class='srclink' href='../../src/core/num/mod.rs.html#71-75' title='goto source code'>[src]</a></div><code>impl<T: <a class="trait" href="../../core/fmt/trait.Octal.html" title="trait core::fmt::Octal">Octal</a>> Octal for <a class="struct" href="../../core/num/struct.Wrapping.html" title="struct core::num::Wrapping">Wrapping</a><T></code></li> <li><div class='out-of-band'><a class='srclink' href='../../src/core/fmt/num.rs.html#148-152' title='goto source code'>[src]</a></div><code>impl Octal for isize</code></li> <li><div class='out-of-band'><a class='srclink' href='../../src/core/fmt/num.rs.html#148-152' title='goto source code'>[src]</a></div><code>impl Octal for usize</code></li> <li><div class='out-of-band'><a class='srclink' href='../../src/core/fmt/num.rs.html#148-152' title='goto source code'>[src]</a></div><code>impl Octal for i8</code></li> <li><div class='out-of-band'><a class='srclink' href='../../src/core/fmt/num.rs.html#148-152' title='goto source code'>[src]</a></div><code>impl Octal for u8</code></li> <li><div class='out-of-band'><a class='srclink' href='../../src/core/fmt/num.rs.html#148-152' title='goto source code'>[src]</a></div><code>impl Octal for i16</code></li> <li><div class='out-of-band'><a class='srclink' href='../../src/core/fmt/num.rs.html#148-152' title='goto source code'>[src]</a></div><code>impl Octal for u16</code></li> <li><div class='out-of-band'><a class='srclink' href='../../src/core/fmt/num.rs.html#148-152' title='goto source code'>[src]</a></div><code>impl Octal for i32</code></li> <li><div class='out-of-band'><a class='srclink' href='../../src/core/fmt/num.rs.html#148-152' title='goto source code'>[src]</a></div><code>impl Octal for u32</code></li> <li><div class='out-of-band'><a class='srclink' href='../../src/core/fmt/num.rs.html#148-152' title='goto source code'>[src]</a></div><code>impl Octal for i64</code></li> <li><div class='out-of-band'><a class='srclink' href='../../src/core/fmt/num.rs.html#148-152' title='goto source code'>[src]</a></div><code>impl Octal for u64</code></li> <li><div class='out-of-band'><a class='srclink' href='../../src/core/fmt/num.rs.html#148-152' title='goto source code'>[src]</a></div><code>impl Octal for i128</code></li> <li><div class='out-of-band'><a class='srclink' href='../../src/core/fmt/num.rs.html#148-152' title='goto source code'>[src]</a></div><code>impl Octal for u128</code></li> <li><div class='out-of-band'><a class='srclink' href='../../src/core/fmt/mod.rs.html#1565-1567' title='goto source code'>[src]</a></div><code>impl<'a, T: ?<a class="trait" href="../../core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + <a class="trait" href="../../core/fmt/trait.Octal.html" title="trait core::fmt::Octal">Octal</a>> Octal for &'a T</code></li> <li><div class='out-of-band'><a class='srclink' href='../../src/core/fmt/mod.rs.html#1569-1571' title='goto source code'>[src]</a></div><code>impl<'a, T: ?<a class="trait" href="../../core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a> + <a class="trait" href="../../core/fmt/trait.Octal.html" title="trait core::fmt::Octal">Octal</a>> Octal for &'a mut T</code></li> </ul><script type="text/javascript" async src="../../implementors/core/fmt/trait.Octal.js"> </script></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> </div> </div> </aside> <script> window.rootPath = "../../"; window.currentCrate = "core"; </script> <script src="../../main.js"></script> <script defer src="../../search-index.js"></script> </body> </html>