<! 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 `read` fn in crate `std`." >
    <meta name="keywords" content="rust, rustlang, rust-lang, read">

    <title>std::ptr::read - Rust</title>

    <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">
    <! --[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='' width='100'></a>
        <p class='location'><a href='../index.html'>std</a>::<wbr><a href='index.html'>ptr</a></p><script>window.sidebarCurrent = {name: 'read', ty: 'fn', 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 fn">
<h1 class='fqn'><span class='in-band'>Function <a href='../index.html'>std</a>::<wbr><a href='index.html'>ptr</a>::<wbr><a class='fn' href=''>read</a></span><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'>&#x2212;</span>]
            </a>
        </span><a id='src-5203' class='srclink' href='../../core/ptr/fn.read.html?gotosrc=5203' title='goto source code'>[src]</a></span></h1>
<pre class='rust fn'>pub unsafe fn read&lt;T&gt;(src: <a class='primitive' href='../primitive.pointer.html'>*const T</a>) -&gt; T</pre><div class='docblock'><p>Reads the value from <code>src</code> without moving it.  This leaves the
memory in <code>src</code> unchanged.</p>

<h1 id='safety' class='section-header'><a href='#safety'>Safety</a></h1>
<p>Beyond accepting a raw pointer, this is unsafe because it semantically
moves the value out of <code>src</code> without preventing further usage of <code>src</code>. 
If <code>T</code> is not <code>Copy</code>, then care must be taken to ensure that the value at
<code>src</code> is not used before the data is overwritten again (e.g. with <code>write</code>,
<code>zero_memory</code>, or <code>copy_memory</code>).  Note that <code>*src = foo</code> counts as a use
because it will attempt to drop the value previously at <code>*src</code>.</p>
</div></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>&larrb;</dt>
                    <dd>Move up in search results</dd>
                    <dt>&rarrb;</dt>
                    <dd>Move down in search results</dd>
                    <dt>&#9166;</dt>
                    <dd>Go to active search result</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>)
                </p>
            </div>
        </div>
    </aside>

    

    <script>
        window.rootPath = "../../";
        window.currentCrate = "std";
        window.playgroundUrl = "https://play.rust-lang.org/";
    </script>
    <script src="../../jquery.js"></script>
    <script src="../../main.js"></script>
    <script src="../../playpen.js"></script>
    <script defer src="../../search-index.js"></script>
</body>
</html>