<?xml version="1.0" encoding="utf-8" standalone="yes"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>4.1 常见前置条件 on 编程那些事儿</title><link>https://before80.github.io/prgms/Rust/comprehensiveRust/unsafe/safety-preconditions/common-preconditions/</link><description>Recent content in 4.1 常见前置条件 on 编程那些事儿</description><generator>Hugo</generator><language>zh-cn</language><lastBuildDate>Tue, 11 Aug 2026 23:57:44 +0800</lastBuildDate><atom:link href="https://before80.github.io/prgms/Rust/comprehensiveRust/unsafe/safety-preconditions/common-preconditions/index.xml" rel="self" type="application/rss+xml"/><item><title>4.1.1 Getter 示例</title><link>https://before80.github.io/prgms/Rust/comprehensiveRust/unsafe/safety-preconditions/common-preconditions/01-getter/</link><pubDate>Tue, 11 Aug 2026 11:30:00 +0800</pubDate><guid>https://before80.github.io/prgms/Rust/comprehensiveRust/unsafe/safety-preconditions/common-preconditions/01-getter/</guid><description>&lt;blockquote&gt;
&lt;p&gt;译文 · 基于 &lt;a href="https://google.github.io/comprehensive-rust/"&gt;Comprehensive Rust&lt;/a&gt;&lt;/p&gt;
&lt;/blockquote&gt;
&lt;blockquote&gt;
&lt;p&gt;原文链接: &lt;a href="https://google.github.io/comprehensive-rust/unsafe-deep-dive/safety-preconditions/getter.html"&gt;https://google.github.io/comprehensive-rust/unsafe-deep-dive/safety-preconditions/getter.html&lt;/a&gt;&lt;/p&gt;
&lt;/blockquote&gt;
&lt;h1 id="411-getter-示例"&gt;4.1.1 Getter 示例&lt;/h1&gt;
&lt;div class="highlight"&gt;&lt;div style="color:#b0c4de;background-color:#282c34;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;
&lt;table style="border-spacing:0;padding:0;margin:0;border:0;"&gt;&lt;tr&gt;&lt;td style="vertical-align:top;padding:0;margin:0;border:0;"&gt;
&lt;pre tabindex="0" style="color:#b0c4de;background-color:#282c34;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt;1
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt;2
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt;3
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt;4
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt;5
&lt;/span&gt;&lt;span style="white-space:pre;-webkit-user-select:none;user-select:none;margin-right:0.4em;padding:0 0.4em 0 0.4em;color:#58626f"&gt;6
&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/td&gt;
&lt;td style="vertical-align:top;padding:0;margin:0;border:0;;width:100%"&gt;
&lt;pre tabindex="0" style="color:#b0c4de;background-color:#282c34;-moz-tab-size:4;-o-tab-size:4;tab-size:4;-webkit-text-size-adjust:none;"&gt;&lt;code class="language-rust" data-lang="rust"&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#8a93a5;font-style:italic"&gt;// Copyright 2026 Google LLC
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#8a93a5;font-style:italic"&gt;// SPDX-License-Identifier: Apache-2.0
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#7e97c3"&gt;/// 返回 `arr` 中 `index` 位置的元素
&lt;/span&gt;&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#76a9f9"&gt;unsafe&lt;/span&gt; &lt;span style="color:#76a9f9"&gt;fn&lt;/span&gt; &lt;span style="color:#00b1f7"&gt;get&lt;/span&gt;&lt;span style="color:#abb2bf"&gt;(&lt;/span&gt;&lt;span style="color:#aa89ea"&gt;arr&lt;/span&gt;: &lt;span style="color:#54b1c7"&gt;*&lt;/span&gt;&lt;span style="color:#76a9f9"&gt;const&lt;/span&gt; &lt;span style="color:#e5c07b"&gt;i32&lt;/span&gt;&lt;span style="color:#abb2bf"&gt;,&lt;/span&gt; &lt;span style="color:#aa89ea"&gt;index&lt;/span&gt;: &lt;span style="color:#e5c07b"&gt;usize&lt;/span&gt;&lt;span style="color:#abb2bf"&gt;)&lt;/span&gt; -&amp;gt; &lt;span style="color:#e5c07b"&gt;i32&lt;/span&gt; &lt;span style="color:#abb2bf"&gt;{&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt; &lt;span style="color:#76a9f9"&gt;unsafe&lt;/span&gt; &lt;span style="color:#abb2bf"&gt;{&lt;/span&gt; &lt;span style="color:#54b1c7"&gt;*&lt;/span&gt;&lt;span style="color:#aa89ea"&gt;arr&lt;/span&gt;&lt;span style="color:#abb2bf"&gt;.&lt;/span&gt;&lt;span style="color:#aa89ea"&gt;add&lt;/span&gt;&lt;span style="color:#abb2bf"&gt;(&lt;/span&gt;&lt;span style="color:#aa89ea"&gt;index&lt;/span&gt;&lt;span style="color:#abb2bf"&gt;)&lt;/span&gt; &lt;span style="color:#abb2bf"&gt;}&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;span style="display:flex;"&gt;&lt;span&gt;&lt;span style="color:#abb2bf"&gt;}&lt;/span&gt;
&lt;/span&gt;&lt;/span&gt;&lt;/code&gt;&lt;/pre&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;
&lt;/div&gt;
&lt;/div&gt;&lt;blockquote&gt;
&lt;p&gt;「安全前置条件是指代码上必须满足的条件，以维持 Rust 的安全保证。&lt;/p&gt;</description></item></channel></rss>