| <!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="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/itertools-0.8.2/src/zip_longest.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>zip_longest.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../source-script.js"></script><script defer src="../../source-files.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../itertools/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../itertools/index.html"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="kw">use </span>std::cmp::Ordering::{Equal, Greater, Less}; |
| <span class="kw">use </span><span class="kw">super</span>::size_hint; |
| <span class="kw">use </span>std::iter::Fuse; |
| |
| <span class="kw">use </span>either_or_both::EitherOrBoth; |
| |
| <span class="comment">// ZipLongest originally written by SimonSapin, |
| // and dedicated to itertools https://github.com/rust-lang/rust/pull/19283 |
| |
| </span><span class="doccomment">/// An iterator which iterates two other iterators simultaneously |
| /// |
| /// This iterator is *fused*. |
| /// |
| /// See [`.zip_longest()`](../trait.Itertools.html#method.zip_longest) for more information. |
| </span><span class="attribute">#[derive(Clone, Debug)] |
| #[must_use = <span class="string">"iterator adaptors are lazy and do nothing unless consumed"</span>] |
| </span><span class="kw">pub struct </span>ZipLongest<T, U> { |
| a: Fuse<T>, |
| b: Fuse<U>, |
| } |
| |
| <span class="doccomment">/// Create a new `ZipLongest` iterator. |
| </span><span class="kw">pub fn </span>zip_longest<T, U>(a: T, b: U) -> ZipLongest<T, U> |
| <span class="kw">where </span>T: Iterator, |
| U: Iterator |
| { |
| ZipLongest { |
| a: a.fuse(), |
| b: b.fuse(), |
| } |
| } |
| |
| <span class="kw">impl</span><T, U> Iterator <span class="kw">for </span>ZipLongest<T, U> |
| <span class="kw">where </span>T: Iterator, |
| U: Iterator |
| { |
| <span class="kw">type </span>Item = EitherOrBoth<T::Item, U::Item>; |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>next(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>::Item> { |
| <span class="kw">match </span>(<span class="self">self</span>.a.next(), <span class="self">self</span>.b.next()) { |
| (<span class="prelude-val">None</span>, <span class="prelude-val">None</span>) => <span class="prelude-val">None</span>, |
| (<span class="prelude-val">Some</span>(a), <span class="prelude-val">None</span>) => <span class="prelude-val">Some</span>(EitherOrBoth::Left(a)), |
| (<span class="prelude-val">None</span>, <span class="prelude-val">Some</span>(b)) => <span class="prelude-val">Some</span>(EitherOrBoth::Right(b)), |
| (<span class="prelude-val">Some</span>(a), <span class="prelude-val">Some</span>(b)) => <span class="prelude-val">Some</span>(EitherOrBoth::Both(a, b)), |
| } |
| } |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>size_hint(<span class="kw-2">&</span><span class="self">self</span>) -> (usize, <span class="prelude-ty">Option</span><usize>) { |
| size_hint::max(<span class="self">self</span>.a.size_hint(), <span class="self">self</span>.b.size_hint()) |
| } |
| } |
| |
| <span class="kw">impl</span><T, U> DoubleEndedIterator <span class="kw">for </span>ZipLongest<T, U> |
| <span class="kw">where </span>T: DoubleEndedIterator + ExactSizeIterator, |
| U: DoubleEndedIterator + ExactSizeIterator |
| { |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>next_back(<span class="kw-2">&mut </span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="self">Self</span>::Item> { |
| <span class="kw">match </span><span class="self">self</span>.a.len().cmp(<span class="kw-2">&</span><span class="self">self</span>.b.len()) { |
| Equal => <span class="kw">match </span>(<span class="self">self</span>.a.next_back(), <span class="self">self</span>.b.next_back()) { |
| (<span class="prelude-val">None</span>, <span class="prelude-val">None</span>) => <span class="prelude-val">None</span>, |
| (<span class="prelude-val">Some</span>(a), <span class="prelude-val">Some</span>(b)) => <span class="prelude-val">Some</span>(EitherOrBoth::Both(a, b)), |
| <span class="comment">// These can only happen if .len() is inconsistent with .next_back() |
| </span>(<span class="prelude-val">Some</span>(a), <span class="prelude-val">None</span>) => <span class="prelude-val">Some</span>(EitherOrBoth::Left(a)), |
| (<span class="prelude-val">None</span>, <span class="prelude-val">Some</span>(b)) => <span class="prelude-val">Some</span>(EitherOrBoth::Right(b)), |
| }, |
| Greater => <span class="self">self</span>.a.next_back().map(EitherOrBoth::Left), |
| Less => <span class="self">self</span>.b.next_back().map(EitherOrBoth::Right), |
| } |
| } |
| } |
| |
| <span class="kw">impl</span><T, U> ExactSizeIterator <span class="kw">for </span>ZipLongest<T, U> |
| <span class="kw">where </span>T: ExactSizeIterator, |
| U: ExactSizeIterator |
| {} |
| </code></pre></div> |
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