oxipng/doc/bitflags/__core/ptr/fn.read.html
2016-04-20 15:59:23 -04:00

131 lines
No EOL
5.7 KiB
HTML
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!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 `bitflags`.">
<meta name="keywords" content="rust, rustlang, rust-lang, read">
<title>bitflags::__core::ptr::read - Rust</title>
<link rel="stylesheet" type="text/css" href="../../../rustdoc.css">
<link rel="stylesheet" type="text/css" href="../../../main.css">
</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">
<p class='location'><a href='../../index.html'>bitflags</a>::<wbr><a href='../index.html'>__core</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'>bitflags</a>::<wbr><a href='../index.html'>__core</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-5855' class='srclink' href='https://doc.rust-lang.org/nightly/core/ptr/fn.read.html?gotosrc=5855' title='goto source code'>[src]</a></span></h1>
<pre class='rust fn'>pub unsafe fn read&lt;T&gt;(src: <a class='primitive' href='https://doc.rust-lang.org/nightly/bitflags/primitive.pointer.html'>*const T</a>) -&gt; T</pre><span class="since">1.0.0</span><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>
<h1 id='examples' class='section-header'><a href='#examples'>Examples</a></h1>
<p>Basic usage:</p>
<pre class='rust rust-example-rendered'>
<span class='kw'>let</span> <span class='ident'>x</span> <span class='op'>=</span> <span class='number'>12</span>;
<span class='kw'>let</span> <span class='ident'>y</span> <span class='op'>=</span> <span class='kw-2'>&amp;</span><span class='ident'>x</span> <span class='kw'>as</span> <span class='op'>*</span><span class='kw'>const</span> <span class='ident'>i32</span>;
<span class='kw'>unsafe</span> { <span class='macro'>println</span><span class='macro'>!</span>(<span class='string'>&quot;{}&quot;</span>, <span class='ident'>std</span>::<span class='ident'>ptr</span>::<span class='ident'>read</span>(<span class='ident'>y</span>)); }</pre>
</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> or <code>* -> vec</code>)
</p>
</div>
</div>
</aside>
<script>
window.rootPath = "../../../";
window.currentCrate = "bitflags";
window.playgroundUrl = "";
</script>
<script src="../../../jquery.js"></script>
<script src="../../../main.js"></script>
<script defer src="../../../search-index.js"></script>
</body>
</html>