<!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 `clone` mod in crate `std`."> <meta name="keywords" content="rust, rustlang, rust-lang, clone"> <title>std::clone - Rust</title> <link rel="stylesheet" type="text/css" href="../../normalize.css"> <link rel="stylesheet" type="text/css" href="../../rustdoc.css"> <link rel="stylesheet" type="text/css" href="../../main.css"> <link rel="shortcut icon" href="https://doc.rust-lang.org/favicon.ico"> </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"> <a href='../../std/index.html'><img src='https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png' alt='logo' width='100'></a> <p class='location'>Module clone</p><div class="block items"><ul><li><a href="#traits">Traits</a></li></ul></div><p class='location'><a href='../index.html'>std</a></p><script>window.sidebarCurrent = {name: 'clone', ty: 'mod', relpath: '../'};</script><script defer src="../sidebar-items.js"></script> </nav> <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'>Module <a href='../index.html'>std</a>::<wbr><a class="mod" href=''>clone</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/clone.rs.html#11-170' title='goto source code'>[src]</a></span></h1> <div class='docblock'><p>The <code>Clone</code> trait for types that cannot be 'implicitly copied'.</p> <p>In Rust, some simple types are "implicitly copyable" and when you assign them or pass them as arguments, the receiver will get a copy, leaving the original value in place. These types do not require allocation to copy and do not have finalizers (i.e. they do not contain owned boxes or implement <a href="../../std/ops/trait.Drop.html"><code>Drop</code></a>), so the compiler considers them cheap and safe to copy. For other types copies must be made explicitly, by convention implementing the <a href="trait.Clone.html"><code>Clone</code></a> trait and calling the <a href="trait.Clone.html#tymethod.clone"><code>clone</code></a> method.</p> <p>Basic usage example:</p> <pre class="rust rust-example-rendered"> <span class="kw">let</span> <span class="ident">s</span> <span class="op">=</span> <span class="ident">String</span>::<span class="ident">new</span>(); <span class="comment">// String type implements Clone</span> <span class="kw">let</span> <span class="ident">copy</span> <span class="op">=</span> <span class="ident">s</span>.<span class="ident">clone</span>(); <span class="comment">// so we can clone it</span><a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=fn%20main()%20%7B%0Alet%20s%20%3D%20String%3A%3Anew()%3B%20%2F%2F%20String%20type%20implements%20Clone%0Alet%20copy%20%3D%20s.clone()%3B%20%2F%2F%20so%20we%20can%20clone%20it%0A%7D">Run</a></pre> <p>To easily implement the Clone trait, you can also use <code>#[derive(Clone)]</code>. Example:</p> <pre class="rust rust-example-rendered"> <span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Clone</span>)]</span> <span class="comment">// we add the Clone trait to Morpheus struct</span> <span class="kw">struct</span> <span class="ident">Morpheus</span> { <span class="ident">blue_pill</span>: <span class="ident">f32</span>, <span class="ident">red_pill</span>: <span class="ident">i64</span>, } <span class="kw">fn</span> <span class="ident">main</span>() { <span class="kw">let</span> <span class="ident">f</span> <span class="op">=</span> <span class="ident">Morpheus</span> { <span class="ident">blue_pill</span>: <span class="number">0.0</span>, <span class="ident">red_pill</span>: <span class="number">0</span> }; <span class="kw">let</span> <span class="ident">copy</span> <span class="op">=</span> <span class="ident">f</span>.<span class="ident">clone</span>(); <span class="comment">// and now we can clone it!</span> }<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=%23%5Bderive(Clone)%5D%20%2F%2F%20we%20add%20the%20Clone%20trait%20to%20Morpheus%20struct%0Astruct%20Morpheus%20%7B%0A%20%20%20blue_pill%3A%20f32%2C%0A%20%20%20red_pill%3A%20i64%2C%0A%7D%0A%0Afn%20main()%20%7B%0A%20%20%20let%20f%20%3D%20Morpheus%20%7B%20blue_pill%3A%200.0%2C%20red_pill%3A%200%20%7D%3B%0A%20%20%20let%20copy%20%3D%20f.clone()%3B%20%2F%2F%20and%20now%20we%20can%20clone%20it!%0A%7D%0A">Run</a></pre> </div><h2 id='traits' class='section-header'><a href="#traits">Traits</a></h2> <table> <tr class=' module-item'> <td><a class="trait" href="trait.Clone.html" title='trait std::clone::Clone'>Clone</a></td> <td class='docblock-short'> <p>A common trait for the ability to explicitly duplicate an object.</p> </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>?</dt> <dd>Show this help dialog</dd> <dt>S</dt> <dd>Focus the search field</dd> <dt>⇤</dt> <dd>Move up in search results</dd> <dt>⇥</dt> <dd>Move down in search results</dd> <dt>⏎</dt> <dd>Go to active search result</dd> <dt>+</dt> <dd>Collapse/expand 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 = "std"; </script> <script src="../../main.js"></script> <script defer src="../../search-index.js"></script> </body> </html>