33 lines
6.2 KiB
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33 lines
6.2 KiB
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<!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="Polls multiple futures simultaneously, resolving to a `Result` containing either a tuple of the successful outputs or an error."><title>try_join in futures_util - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Italic-81dc35de.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-MediumItalic-ccf7e434.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2"href="../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../static.files/rustdoc-ca0dd0c4.css"><meta name="rustdoc-vars" data-root-path="../" data-static-root-path="../static.files/" data-current-crate="futures_util" data-themes="" data-resource-suffix="" data-rustdoc-version="1.93.1 (01f6ddf75 2026-02-11) (Arch Linux rust 1:1.93.1-1)" data-channel="1.93.1" data-search-js="search-9e2438ea.js" data-stringdex-js="stringdex-a3946164.js" data-settings-js="settings-c38705f0.js" ><script src="../static.files/storage-e2aeef58.js"></script><script defer src="sidebar-items.js"></script><script defer src="../static.files/main-a410ff4d.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-263c88ec.css"></noscript><link rel="alternate icon" type="image/png" href="../static.files/favicon-32x32-eab170b8.png"><link rel="icon" type="image/svg+xml" href="../static.files/favicon-044be391.svg"></head><body class="rustdoc macro"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><rustdoc-topbar><h2><a href="#">try_join</a></h2></rustdoc-topbar><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../futures_util/index.html">futures_<wbr>util</a><span class="version">0.3.32</span></h2></div><div class="sidebar-elems"><section id="rustdoc-toc"><h2 class="location"><a href="#">try_<wbr>join</a></h2><h3><a href="#">Sections</a></h3><ul class="block top-toc"><li><a href="#examples" title="Examples">Examples</a></li></ul></section><div id="rustdoc-modnav"><h2 class="in-crate"><a href="index.html">In crate futures_<wbr>util</a></h2></div></div></nav><div class="sidebar-resizer" title="Drag to resize sidebar"></div><main><div class="width-limiter"><section id="main-content" class="content"><div class="main-heading"><div class="rustdoc-breadcrumbs"><a href="index.html">futures_util</a></div><h1>Macro <span class="macro">try_<wbr>join</span> <button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"><a class="src" href="../src/futures_util/async_await/join_mod.rs.html#102-109">Source</a> </span></div><pre class="rust item-decl"><code>macro_rules! try_join {
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($($tokens:tt)*) => { ... };
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}</code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Polls multiple futures simultaneously, resolving to a <a href="https://doc.rust-lang.org/1.93.1/core/result/enum.Result.html" title="enum core::result::Result"><code>Result</code></a> containing
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either a tuple of the successful outputs or an error.</p>
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<p><code>try_join!</code> is similar to <a href="macro.join.html" title="macro futures_util::join"><code>join!</code></a>, but completes immediately if any of
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the futures return an error.</p>
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<p>This macro is only usable inside of async functions, closures, and blocks.
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It is also gated behind the <code>async-await</code> feature of this library, which is
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activated by default.</p>
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<h2 id="examples"><a class="doc-anchor" href="#examples">§</a>Examples</h2>
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<p>When used on multiple futures that return <code>Ok</code>, <code>try_join!</code> will return
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<code>Ok</code> of a tuple of the values:</p>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>futures::try_join;
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<span class="kw">let </span>a = <span class="kw">async </span>{ <span class="prelude-val">Ok</span>::<i32, i32>(<span class="number">1</span>) };
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<span class="kw">let </span>b = <span class="kw">async </span>{ <span class="prelude-val">Ok</span>::<i32, i32>(<span class="number">2</span>) };
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<span class="macro">assert_eq!</span>(<span class="macro">try_join!</span>(a, b), <span class="prelude-val">Ok</span>((<span class="number">1</span>, <span class="number">2</span>)));
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<span class="comment">// `try_join!` is variadic, so you can pass any number of futures
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</span><span class="kw">let </span>c = <span class="kw">async </span>{ <span class="prelude-val">Ok</span>::<i32, i32>(<span class="number">3</span>) };
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<span class="kw">let </span>d = <span class="kw">async </span>{ <span class="prelude-val">Ok</span>::<i32, i32>(<span class="number">4</span>) };
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<span class="kw">let </span>e = <span class="kw">async </span>{ <span class="prelude-val">Ok</span>::<i32, i32>(<span class="number">5</span>) };
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<span class="macro">assert_eq!</span>(<span class="macro">try_join!</span>(c, d, e), <span class="prelude-val">Ok</span>((<span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>)));</code></pre></div>
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<p>If one of the futures resolves to an error, <code>try_join!</code> will return
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that error:</p>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>futures::try_join;
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<span class="kw">let </span>a = <span class="kw">async </span>{ <span class="prelude-val">Ok</span>::<i32, i32>(<span class="number">1</span>) };
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<span class="kw">let </span>b = <span class="kw">async </span>{ <span class="prelude-val">Err</span>::<u64, i32>(<span class="number">2</span>) };
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<span class="macro">assert_eq!</span>(<span class="macro">try_join!</span>(a, b), <span class="prelude-val">Err</span>(<span class="number">2</span>));</code></pre></div></div></details></section></div></main></body></html> |