| <!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/indexmap-1.9.3/src/mutable_keys.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>mutable_keys.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="../../indexmap/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="../../indexmap/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>core::hash::{BuildHasher, Hash}; |
| |
| <span class="kw">use super</span>::{Equivalent, IndexMap}; |
| |
| <span class="kw">pub struct </span>PrivateMarker {} |
| |
| <span class="doccomment">/// Opt-in mutable access to keys. |
| /// |
| /// These methods expose `&mut K`, mutable references to the key as it is stored |
| /// in the map. |
| /// You are allowed to modify the keys in the hashmap **if the modification |
| /// does not change the key’s hash and equality**. |
| /// |
| /// If keys are modified erroneously, you can no longer look them up. |
| /// This is sound (memory safe) but a logical error hazard (just like |
| /// implementing PartialEq, Eq, or Hash incorrectly would be). |
| /// |
| /// `use` this trait to enable its methods for `IndexMap`. |
| </span><span class="kw">pub trait </span>MutableKeys { |
| <span class="kw">type </span>Key; |
| <span class="kw">type </span>Value; |
| |
| <span class="doccomment">/// Return item index, mutable reference to key and value |
| </span><span class="kw">fn </span>get_full_mut2<Q: <span class="question-mark">?</span>Sized>( |
| <span class="kw-2">&mut </span><span class="self">self</span>, |
| key: <span class="kw-2">&</span>Q, |
| ) -> <span class="prelude-ty">Option</span><(usize, <span class="kw-2">&mut </span><span class="self">Self</span>::Key, <span class="kw-2">&mut </span><span class="self">Self</span>::Value)> |
| <span class="kw">where |
| </span>Q: Hash + Equivalent<<span class="self">Self</span>::Key>; |
| |
| <span class="doccomment">/// Scan through each key-value pair in the map and keep those where the |
| /// closure `keep` returns `true`. |
| /// |
| /// The elements are visited in order, and remaining elements keep their |
| /// order. |
| /// |
| /// Computes in **O(n)** time (average). |
| </span><span class="kw">fn </span>retain2<F>(<span class="kw-2">&mut </span><span class="self">self</span>, keep: F) |
| <span class="kw">where |
| </span>F: FnMut(<span class="kw-2">&mut </span><span class="self">Self</span>::Key, <span class="kw-2">&mut </span><span class="self">Self</span>::Value) -> bool; |
| |
| <span class="doccomment">/// This method is not useful in itself – it is there to “seal” the trait |
| /// for external implementation, so that we can add methods without |
| /// causing breaking changes. |
| </span><span class="kw">fn </span>__private_marker(<span class="kw-2">&</span><span class="self">self</span>) -> PrivateMarker; |
| } |
| |
| <span class="doccomment">/// Opt-in mutable access to keys. |
| /// |
| /// See [`MutableKeys`](trait.MutableKeys.html) for more information. |
| </span><span class="kw">impl</span><K, V, S> MutableKeys <span class="kw">for </span>IndexMap<K, V, S> |
| <span class="kw">where |
| </span>K: Eq + Hash, |
| S: BuildHasher, |
| { |
| <span class="kw">type </span>Key = K; |
| <span class="kw">type </span>Value = V; |
| <span class="kw">fn </span>get_full_mut2<Q: <span class="question-mark">?</span>Sized>(<span class="kw-2">&mut </span><span class="self">self</span>, key: <span class="kw-2">&</span>Q) -> <span class="prelude-ty">Option</span><(usize, <span class="kw-2">&mut </span>K, <span class="kw-2">&mut </span>V)> |
| <span class="kw">where |
| </span>Q: Hash + Equivalent<K>, |
| { |
| <span class="self">self</span>.get_full_mut2_impl(key) |
| } |
| |
| <span class="kw">fn </span>retain2<F>(<span class="kw-2">&mut </span><span class="self">self</span>, keep: F) |
| <span class="kw">where |
| </span>F: FnMut(<span class="kw-2">&mut </span>K, <span class="kw-2">&mut </span>V) -> bool, |
| { |
| <span class="self">self</span>.retain_mut(keep) |
| } |
| |
| <span class="kw">fn </span>__private_marker(<span class="kw-2">&</span><span class="self">self</span>) -> PrivateMarker { |
| PrivateMarker {} |
| } |
| } |
| </code></pre></div> |
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