servius/google_speech_rs
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
e9a232e07da2cea370f1a38dee4419ca603c646a
google_speech_rs/docs/ctor/attr.ctor.html
T
github-actions[bot] e9a232e07d Auto Generated Documentation
2021-06-27 15:50:04 +00:00

60 lines
9.3 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="Marks a function or static variable as a library/executable constructor. This uses OS-specific linker sections to call a specific function at load time."><meta name="keywords" content="rust, rustlang, rust-lang, ctor"><title>ctor in ctor - 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="../light.css" id="themeStyle"><link rel="stylesheet" type="text/css" href="../dark.css" disabled ><link rel="stylesheet" type="text/css" href="../ayu.css" disabled ><script id="default-settings"></script><script src="../storage.js"></script><script src="../crates.js"></script><noscript><link rel="stylesheet" href="../noscript.css"></noscript><link rel="icon" type="image/svg+xml" href="../favicon.svg">
<link rel="alternate icon" type="image/png" href="../favicon-16x16.png">
<link rel="alternate icon" type="image/png" href="../favicon-32x32.png"><style type="text/css">#crate-search{background-image:url("../down-arrow.svg");}</style></head><body class="rustdoc attr"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu" role="button">&#9776;</div><a href='../ctor/index.html'><div class='logo-container rust-logo'><img src='../rust-logo.png' alt='logo'></div></a><div class="sidebar-elems"><p class="location"><a href="index.html">ctor</a></p><div id="sidebar-vars" data-name="ctor" data-ty="attr" data-relpath=""></div><script defer src="sidebar-items.js"></script></div></nav><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!" aria-haspopup="menu"><img src="../brush.svg" width="18" height="18" alt="Pick another theme!"></button><div id="theme-choices" role="menu"></div></div><nav class="sub"><form class="search-form"><div class="search-container"><div><select id="crate-search"><option value="All crates">All crates</option></select><input class="search-input" name="search" disabled autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"></div><button type="button" class="help-button">?</button>
<a id="settings-menu" href="../settings.html"><img src="../wheel.svg" width="18" height="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><h1 class="fqn"><span class="in-band">Attribute Macro <a href="index.html">ctor</a>::<wbr><a class="attr" href="">ctor</a><button id="copy-path" onclick="copy_path(this)">⎘</button></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 class="srclink" href="../src/ctor/lib.rs.html#114-258" title="goto source code">[src]</a></span></h1><pre class="rust attr">#[ctor]</pre><div class="docblock"><p>Marks a function or static variable as a library/executable constructor.
This uses OS-specific linker sections to call a specific function at
load time.</p>
<p>Multiple startup functions/statics are supported, but the invocation order is not
guaranteed.</p>
<h1 id="examples" class="section-header"><a href="#examples">Examples</a></h1>
<p>Print a startup message:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="attribute">#[<span class="ident">ctor</span>]</span>
<span class="kw">fn</span> <span class="ident">foo</span>() {
<span class="macro">println!</span>(<span class="string">&quot;Hello, world!&quot;</span>);
}
<span class="macro">println!</span>(<span class="string">&quot;main()&quot;</span>);</pre></div>
<p>Make changes to <code>static</code> variables:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="kw">static</span> <span class="ident">INITED</span>: <span class="ident">AtomicBool</span> <span class="op">=</span> <span class="ident">AtomicBool::new</span>(<span class="bool-val">false</span>);
<span class="attribute">#[<span class="ident">ctor</span>]</span>
<span class="kw">fn</span> <span class="ident">foo</span>() {
<span class="ident">INITED</span>.<span class="ident">store</span>(<span class="bool-val">true</span>, <span class="ident">Ordering::SeqCst</span>);
}</pre></div>
<p>Initialize a <code>HashMap</code> at startup time:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="attribute">#[<span class="ident">ctor</span>]</span>
<span class="kw">static</span> <span class="ident">STATIC_CTOR</span>: <span class="ident">HashMap</span><span class="op">&lt;</span><span class="ident">u32</span>, <span class="ident">String</span><span class="op">&gt;</span> <span class="op">=</span> {
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">m</span> <span class="op">=</span> <span class="ident">HashMap::new</span>();
<span class="kw">for</span> <span class="ident">i</span> <span class="kw">in</span> <span class="number">0</span>..<span class="number">100</span> {
<span class="ident">m</span>.<span class="ident">insert</span>(<span class="ident">i</span>, <span class="macro">format!</span>(<span class="string">&quot;x*100={}&quot;</span>, <span class="ident">i</span><span class="kw-2">*</span><span class="number">100</span>));
}
<span class="ident">m</span>
};
</pre></div>
<h1 id="details" class="section-header"><a href="#details">Details</a></h1>
<p>The <code>#[ctor]</code> macro makes use of linker sections to ensure that a
function is run at startup time.</p>
<p>The above example translates into the following Rust code (approximately):</p>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="attribute">#[<span class="ident">used</span>]</span>
<span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">any</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">&quot;linux&quot;</span>, <span class="ident">target_os</span> <span class="op">=</span> <span class="string">&quot;android&quot;</span>), <span class="ident">link_section</span> <span class="op">=</span> <span class="string">&quot;.init_array&quot;</span>)]</span>
<span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">&quot;freebsd&quot;</span>, <span class="ident">link_section</span> <span class="op">=</span> <span class="string">&quot;.init_array&quot;</span>)]</span>
<span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">&quot;netbsd&quot;</span>, <span class="ident">link_section</span> <span class="op">=</span> <span class="string">&quot;.init_array&quot;</span>)]</span>
<span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">&quot;openbsd&quot;</span>, <span class="ident">link_section</span> <span class="op">=</span> <span class="string">&quot;.init_array&quot;</span>)]</span>
<span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">&quot;illumos&quot;</span>, <span class="ident">link_section</span> <span class="op">=</span> <span class="string">&quot;.init_array&quot;</span>)]</span>
<span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">any</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">&quot;macos&quot;</span>, <span class="ident">target_os</span> <span class="op">=</span> <span class="string">&quot;ios&quot;</span>), <span class="ident">link_section</span> <span class="op">=</span> <span class="string">&quot;__DATA,__mod_init_func&quot;</span>)]</span>
<span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">&quot;windows&quot;</span>, <span class="ident">link_section</span> <span class="op">=</span> <span class="string">&quot;.CRT$XCU&quot;</span>)]</span>
<span class="kw">static</span> <span class="ident">FOO</span>: <span class="kw">extern</span> <span class="kw">fn</span>() <span class="op">=</span> {
<span class="attribute">#[<span class="ident">cfg_attr</span>(<span class="ident">any</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">&quot;linux&quot;</span>, <span class="ident">target_os</span> <span class="op">=</span> <span class="string">&quot;android&quot;</span>), <span class="ident">link_section</span> <span class="op">=</span> <span class="string">&quot;.text.startup&quot;</span>)]</span>
<span class="kw">extern</span> <span class="kw">fn</span> <span class="ident">foo</span>() { <span class="comment">/* ... */</span> };
<span class="ident">foo</span>
};</pre></div>
</div></section><section id="search" class="content hidden"></section><div id="rustdoc-vars" data-root-path="../" data-current-crate="ctor" data-search-index-js="../search-index.js" data-search-js="../search.js"></div>
<script src="../main.js"></script></body></html>
Reference in New Issue View Git Blame Copy Permalink