itertools/fn.concat.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="Combine all an iterator’s elements into one element by using `Extend`."><title>concat in itertools - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Regular-0fe48ade.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" crossorigin href="../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../static.files/rustdoc-46132b98.css"><meta name="rustdoc-vars" data-root-path="../" data-static-root-path="../static.files/" data-current-crate="itertools" data-themes="" data-resource-suffix="" data-rustdoc-version="1.85.0 (4d91de4e4 2025-02-17)" data-channel="1.85.0" data-search-js="search-75f5ac3e.js" data-settings-js="settings-0f613d39.js" ><script src="../static.files/storage-59e33391.js"></script><script defer src="sidebar-items.js"></script><script defer src="../static.files/main-5f194d8c.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-893ab5e7.css"></noscript><link rel="alternate icon" type="image/png" href="../static.files/favicon-32x32-6580c154.png"><link rel="icon" type="image/svg+xml" href="../static.files/favicon-044be391.svg"></head><body class="rustdoc fn"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle" title="show sidebar"></button></nav><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../itertools/index.html">itertools</a><span class="version">0.13.0</span></h2></div><div class="sidebar-elems"><div id="rustdoc-modnav"></div></div></nav><div class="sidebar-resizer"></div><main><div class="width-limiter"><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><span class="rustdoc-breadcrumbs"><a href="index.html">itertools</a></span><h1>Function <span class="fn">concat</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/itertools/concat_impl.rs.html#17-30">Source</a> </span></div><pre class="rust item-decl"><code>pub fn concat&lt;I&gt;(iterable: I) -&gt; I::<a class="associatedtype" href="https://doc.rust-lang.org/1.85.0/core/iter/traits/collect/trait.IntoIterator.html#associatedtype.Item" title="type core::iter::traits::collect::IntoIterator::Item">Item</a><div class="where">where
    I: <a class="trait" href="https://doc.rust-lang.org/1.85.0/core/iter/traits/collect/trait.IntoIterator.html" title="trait core::iter::traits::collect::IntoIterator">IntoIterator</a>,
    I::<a class="associatedtype" href="https://doc.rust-lang.org/1.85.0/core/iter/traits/collect/trait.IntoIterator.html#associatedtype.Item" title="type core::iter::traits::collect::IntoIterator::Item">Item</a>: <a class="trait" href="https://doc.rust-lang.org/1.85.0/core/iter/traits/collect/trait.Extend.html" title="trait core::iter::traits::collect::Extend">Extend</a>&lt;&lt;&lt;I as <a class="trait" href="https://doc.rust-lang.org/1.85.0/core/iter/traits/collect/trait.IntoIterator.html" title="trait core::iter::traits::collect::IntoIterator">IntoIterator</a>&gt;::<a class="associatedtype" href="https://doc.rust-lang.org/1.85.0/core/iter/traits/collect/trait.IntoIterator.html#associatedtype.Item" title="type core::iter::traits::collect::IntoIterator::Item">Item</a> as <a class="trait" href="https://doc.rust-lang.org/1.85.0/core/iter/traits/collect/trait.IntoIterator.html" title="trait core::iter::traits::collect::IntoIterator">IntoIterator</a>&gt;::<a class="associatedtype" href="https://doc.rust-lang.org/1.85.0/core/iter/traits/collect/trait.IntoIterator.html#associatedtype.Item" title="type core::iter::traits::collect::IntoIterator::Item">Item</a>&gt; + <a class="trait" href="https://doc.rust-lang.org/1.85.0/core/iter/traits/collect/trait.IntoIterator.html" title="trait core::iter::traits::collect::IntoIterator">IntoIterator</a> + <a class="trait" href="https://doc.rust-lang.org/1.85.0/core/default/trait.Default.html" title="trait core::default::Default">Default</a>,</div></code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Combine all an iterator’s elements into one element by using <a href="https://doc.rust-lang.org/1.85.0/core/iter/traits/collect/trait.Extend.html" title="trait core::iter::traits::collect::Extend"><code>Extend</code></a>.</p>
<p><a href="https://doc.rust-lang.org/1.85.0/core/iter/traits/collect/trait.IntoIterator.html" title="trait core::iter::traits::collect::IntoIterator"><code>IntoIterator</code></a>-enabled version of <a href="trait.Itertools.html#method.concat" title="method itertools::Itertools::concat"><code>Itertools::concat</code></a>.</p>
<p>This combinator will extend the first item with each of the rest of the
items of the iterator. If the iterator is empty, the default value of
<code>I::Item</code> is returned.</p>

<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>itertools::concat;

<span class="kw">let </span>input = <span class="macro">vec!</span>[<span class="macro">vec!</span>[<span class="number">1</span>], <span class="macro">vec!</span>[<span class="number">2</span>, <span class="number">3</span>], <span class="macro">vec!</span>[<span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>]];
<span class="macro">assert_eq!</span>(concat(input), <span class="macro">vec!</span>[<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>, <span class="number">6</span>]);</code></pre></div>
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