140 lines
No EOL
7.4 KiB
HTML
140 lines
No EOL
7.4 KiB
HTML
<!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 `poll_fn` fn in crate `tokio`.">
|
||
<meta name="keywords" content="rust, rustlang, rust-lang, poll_fn">
|
||
|
||
<title>tokio::prelude::stream::poll_fn - 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="../../../dark.css">
|
||
<link rel="stylesheet" type="text/css" href="../../../light.css" id="themeStyle">
|
||
<script src="../../../storage.js"></script>
|
||
|
||
|
||
|
||
|
||
</head>
|
||
<body class="rustdoc fn">
|
||
<!--[if lte IE 8]>
|
||
<div class="warning">
|
||
This old browser is unsupported and will most likely display funky
|
||
things.
|
||
</div>
|
||
<![endif]-->
|
||
|
||
|
||
|
||
<nav class="sidebar">
|
||
<div class="sidebar-menu">☰</div>
|
||
|
||
<div class="sidebar-elems"><p class='location'><a href='../../index.html'>tokio</a>::<wbr><a href='../index.html'>prelude</a>::<wbr><a href='index.html'>stream</a></p><script>window.sidebarCurrent = {name: 'poll_fn', ty: 'fn', relpath: ''};</script><script defer src="sidebar-items.js"></script></div>
|
||
</nav>
|
||
|
||
<div class="theme-picker">
|
||
<button id="theme-picker" aria-label="Pick another theme!">
|
||
<img src="../../../brush.svg" width="18" alt="Pick another theme!">
|
||
</button>
|
||
<div id="theme-choices"></div>
|
||
</div>
|
||
<script src="../../../theme.js"></script>
|
||
<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'>Function <a href='../../index.html'>tokio</a>::<wbr><a href='../index.html'>prelude</a>::<wbr><a href='index.html'>stream</a>::<wbr><a class="fn" href=''>poll_fn</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'>−</span>]
|
||
</a>
|
||
</span><a class='srclink' href='../../../src/futures/stream/poll_fn.rs.html#32-37' title='goto source code'>[src]</a></span></h1><pre class='rust fn'>pub fn poll_fn<T, E, F>(f: F) -> <a class="struct" href="../../../tokio/prelude/stream/struct.PollFn.html" title="struct tokio::prelude::stream::PollFn">PollFn</a><F> <span class="where fmt-newline">where<br> F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnMut.html" title="trait core::ops::function::FnMut">FnMut</a>() -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><<a class="enum" href="../../../tokio/prelude/enum.Async.html" title="enum tokio::prelude::Async">Async</a><<a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a><T>>, E>, </span></pre><div class='docblock'><p>Creates a new stream wrapping around a function returning <code>Poll</code>.</p>
|
||
<p>Polling the returned stream delegates to the wrapped function.</p>
|
||
<h1 id="examples" class="section-header"><a href="#examples">Examples</a></h1>
|
||
<pre class="rust rust-example-rendered">
|
||
<span class="kw">use</span> <span class="ident">futures</span>::<span class="ident">stream</span>::<span class="ident">poll_fn</span>;
|
||
<span class="kw">use</span> <span class="ident">futures</span>::{<span class="ident">Async</span>, <span class="ident">Poll</span>};
|
||
|
||
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">counter</span> <span class="op">=</span> <span class="number">1usize</span>;
|
||
|
||
<span class="kw">let</span> <span class="ident">read_stream</span> <span class="op">=</span> <span class="ident">poll_fn</span>(<span class="kw">move</span> <span class="op">||</span> <span class="op">-></span> <span class="ident">Poll</span><span class="op"><</span><span class="prelude-ty">Option</span><span class="op"><</span><span class="ident">String</span><span class="op">></span>, <span class="ident">std</span>::<span class="ident">io</span>::<span class="ident">Error</span><span class="op">></span> {
|
||
<span class="kw">if</span> <span class="ident">counter</span> <span class="op">==</span> <span class="number">0</span> { <span class="kw">return</span> <span class="prelude-val">Ok</span>(<span class="ident">Async</span>::<span class="ident">Ready</span>(<span class="prelude-val">None</span>)); }
|
||
<span class="ident">counter</span> <span class="op">-=</span> <span class="number">1</span>;
|
||
<span class="prelude-val">Ok</span>(<span class="ident">Async</span>::<span class="ident">Ready</span>(<span class="prelude-val">Some</span>(<span class="string">"Hello, World!"</span>.<span class="ident">to_owned</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><kbd>?</kbd></dt>
|
||
<dd>Show this help dialog</dd>
|
||
<dt><kbd>S</kbd></dt>
|
||
<dd>Focus the search field</dd>
|
||
<dt><kbd>↑</kbd></dt>
|
||
<dd>Move up in search results</dd>
|
||
<dt><kbd>↓</kbd></dt>
|
||
<dd>Move down in search results</dd>
|
||
<dt><kbd>↹</kbd></dt>
|
||
<dd>Switch tab</dd>
|
||
<dt><kbd>⏎</kbd></dt>
|
||
<dd>Go to active search result</dd>
|
||
<dt><kbd>+</kbd></dt>
|
||
<dd>Expand all sections</dd>
|
||
<dt><kbd>-</kbd></dt>
|
||
<dd>Collapse 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 = "tokio";
|
||
</script>
|
||
<script src="../../../main.js"></script>
|
||
<script defer src="../../../search-index.js"></script>
|
||
</body>
|
||
</html> |