<!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 `Place` trait in crate `core`."> <meta name="keywords" content="rust, rustlang, rust-lang, Place"> <title>core::ops::Place - 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 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"> <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 Place</p><div class="block items"><ul><li><a href="#required-methods">Required Methods</a></li><li><a href="#implementors">Implementors</a></li></ul></div><p class='location'><a href='../index.html'>core</a>::<wbr><a href='index.html'>ops</a></p><script>window.sidebarCurrent = {name: 'Place', ty: 'trait', 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'>Trait <a href='../index.html'>core</a>::<wbr><a href='index.html'>ops</a>::<wbr><a class="trait" href=''>Place</a></span><span class='out-of-band'><span class='since' title='Stable since Rust version '></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/ops.rs.html#2823-2828' title='goto source code'>[src]</a></span></h1> <pre class='rust trait'>pub trait Place<Data: ?<a class="trait" href="../../core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>> { fn <a href='#tymethod.pointer' class='fnname'>pointer</a>(&mut self) -> *mut Data; }</pre><div class='stability'><div class='stab unstable'><span class=microscope>🔬</span> This is a nightly-only experimental API. (<code>placement_new_protocol </code><a href="https://github.com/rust-lang/rust/issues/27779">#27779</a>)</div></div><div class='docblock'><p>Both <code>PLACE <- EXPR</code> and <code>box EXPR</code> desugar into expressions that allocate an intermediate "place" that holds uninitialized state. The desugaring evaluates EXPR, and writes the result at the address returned by the <code>pointer</code> method of this trait.</p> <p>A <code>Place</code> can be thought of as a special representation for a hypothetical <code>&uninit</code> reference (which Rust cannot currently express directly). That is, it represents a pointer to uninitialized storage.</p> <p>The client is responsible for two steps: First, initializing the payload (it can access its address via <code>pointer</code>). Second, converting the agent to an instance of the owning pointer, via the appropriate <code>finalize</code> method (see the <code>InPlace</code>.</p> <p>If evaluating EXPR fails, then it is up to the destructor for the implementation of Place to clean up any intermediate state (e.g. deallocate box storage, pop a stack, etc).</p> </div> <h2 id='required-methods'>Required Methods</h2> <div class='methods'> <h3 id='tymethod.pointer' class='method'><span id='pointer.v' class='invisible'><code>fn <a href='#tymethod.pointer' class='fnname'>pointer</a>(&mut self) -> *mut Data</code></span></h3><div class='stability'><div class='stab unstable'><span class=microscope>🔬</span> This is a nightly-only experimental API. (<code>placement_new_protocol </code><a href="https://github.com/rust-lang/rust/issues/27779">#27779</a>)</div></div><div class='docblock'><p>Returns the address where the input value will be written. Note that the data at this address is generally uninitialized, and thus one should use <code>ptr::write</code> for initializing it.</p> </div></div> <h2 id='implementors'>Implementors</h2> <ul class='item-list' id='implementors-list'> </ul><script type="text/javascript" async src="../../implementors/core/ops/trait.Place.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>?</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 = "core"; </script> <script src="../../main.js"></script> <script defer src="../../search-index.js"></script> </body> </html>