19 lines
4.6 KiB
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19 lines
4.6 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="Macro for unwrapping the left side of an `Either`, which fails early with the opposite side. Can only be used in functions that return `Either` because of the early return of `Right` that it provides."><title>try_left in either - 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="either" 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_left</a></h2></rustdoc-topbar><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../either/index.html">either</a><span class="version">1.15.0</span></h2></div><div class="sidebar-elems"><section id="rustdoc-toc"><h2 class="location"><a href="#">try_<wbr>left</a></h2><h3><a href="#">Sections</a></h3><ul class="block top-toc"><li><a href="#example" title="Example">Example</a></li></ul></section><div id="rustdoc-modnav"><h2 class="in-crate"><a href="index.html">In crate either</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">either</a></div><h1>Macro <span class="macro">try_<wbr>left</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/either/lib.rs.html#113-120">Source</a> </span></div><pre class="rust item-decl"><code>macro_rules! try_left {
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($expr:expr) => { ... };
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}</code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Macro for unwrapping the left side of an <a href="enum.Either.html" title="enum either::Either"><code>Either</code></a>, which fails early
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with the opposite side. Can only be used in functions that return
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<code>Either</code> because of the early return of <code>Right</code> that it provides.</p>
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<p>See also <a href="macro.try_right.html" title="macro either::try_right"><code>try_right!</code></a> for its dual, which applies the same just to the
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right side.</p>
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<h2 id="example"><a class="doc-anchor" href="#example">§</a>Example</h2>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>either::{Either, Left, Right};
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<span class="kw">fn </span>twice(wrapper: Either<u32, <span class="kw-2">&</span>str>) -> Either<u32, <span class="kw-2">&</span>str> {
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<span class="kw">let </span>value = <span class="macro">either::try_left!</span>(wrapper);
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Left(value * <span class="number">2</span>)
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}
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<span class="kw">fn </span>main() {
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<span class="macro">assert_eq!</span>(twice(Left(<span class="number">2</span>)), Left(<span class="number">4</span>));
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<span class="macro">assert_eq!</span>(twice(Right(<span class="string">"ups"</span>)), Right(<span class="string">"ups"</span>));
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}</code></pre></div></div></details></section></div></main></body></html> |