|
|
<!DOCTYPE HTML>
|
|
|
<html lang="zh-CN" class="light" dir="ltr">
|
|
|
<head>
|
|
|
<!-- Book generated using mdBook -->
|
|
|
<meta charset="UTF-8">
|
|
|
<title>错误处理 - Rust语言圣经(Rust Course)</title>
|
|
|
|
|
|
|
|
|
<!-- Custom HTML head -->
|
|
|
|
|
|
<meta name="description" content="">
|
|
|
<meta name="viewport" content="width=device-width, initial-scale=1">
|
|
|
<meta name="theme-color" content="#ffffff">
|
|
|
|
|
|
<link rel="icon" href="../favicon.svg">
|
|
|
<link rel="shortcut icon" href="../favicon.png">
|
|
|
<link rel="stylesheet" href="../css/variables.css">
|
|
|
<link rel="stylesheet" href="../css/general.css">
|
|
|
<link rel="stylesheet" href="../css/chrome.css">
|
|
|
<link rel="stylesheet" href="../css/print.css" media="print">
|
|
|
|
|
|
<!-- Fonts -->
|
|
|
<link rel="stylesheet" href="../FontAwesome/css/font-awesome.css">
|
|
|
<link rel="stylesheet" href="../fonts/fonts.css">
|
|
|
|
|
|
<!-- Highlight.js Stylesheets -->
|
|
|
<link rel="stylesheet" href="../highlight.css">
|
|
|
<link rel="stylesheet" href="../tomorrow-night.css">
|
|
|
<link rel="stylesheet" href="../ayu-highlight.css">
|
|
|
|
|
|
<!-- Custom theme stylesheets -->
|
|
|
<link rel="stylesheet" href="../theme/style.css">
|
|
|
|
|
|
</head>
|
|
|
<body class="sidebar-visible no-js">
|
|
|
<div id="body-container">
|
|
|
<!-- Provide site root to javascript -->
|
|
|
<script>
|
|
|
var path_to_root = "../";
|
|
|
var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "navy" : "light";
|
|
|
</script>
|
|
|
|
|
|
<!-- Work around some values being stored in localStorage wrapped in quotes -->
|
|
|
<script>
|
|
|
try {
|
|
|
var theme = localStorage.getItem('mdbook-theme');
|
|
|
var sidebar = localStorage.getItem('mdbook-sidebar');
|
|
|
|
|
|
if (theme.startsWith('"') && theme.endsWith('"')) {
|
|
|
localStorage.setItem('mdbook-theme', theme.slice(1, theme.length - 1));
|
|
|
}
|
|
|
|
|
|
if (sidebar.startsWith('"') && sidebar.endsWith('"')) {
|
|
|
localStorage.setItem('mdbook-sidebar', sidebar.slice(1, sidebar.length - 1));
|
|
|
}
|
|
|
} catch (e) { }
|
|
|
</script>
|
|
|
|
|
|
<!-- Set the theme before any content is loaded, prevents flash -->
|
|
|
<script>
|
|
|
var theme;
|
|
|
try { theme = localStorage.getItem('mdbook-theme'); } catch(e) { }
|
|
|
if (theme === null || theme === undefined) { theme = default_theme; }
|
|
|
var html = document.querySelector('html');
|
|
|
html.classList.remove('light')
|
|
|
html.classList.add(theme);
|
|
|
var body = document.querySelector('body');
|
|
|
body.classList.remove('no-js')
|
|
|
body.classList.add('js');
|
|
|
</script>
|
|
|
|
|
|
<input type="checkbox" id="sidebar-toggle-anchor" class="hidden">
|
|
|
|
|
|
<!-- Hide / unhide sidebar before it is displayed -->
|
|
|
<script>
|
|
|
var body = document.querySelector('body');
|
|
|
var sidebar = null;
|
|
|
var sidebar_toggle = document.getElementById("sidebar-toggle-anchor");
|
|
|
if (document.body.clientWidth >= 1080) {
|
|
|
try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
|
|
|
sidebar = sidebar || 'visible';
|
|
|
} else {
|
|
|
sidebar = 'hidden';
|
|
|
}
|
|
|
sidebar_toggle.checked = sidebar === 'visible';
|
|
|
body.classList.remove('sidebar-visible');
|
|
|
body.classList.add("sidebar-" + sidebar);
|
|
|
</script>
|
|
|
|
|
|
<nav id="sidebar" class="sidebar" aria-label="Table of contents">
|
|
|
<div class="sidebar-scrollbox">
|
|
|
<ol class="chapter"><li class="chapter-item affix "><a href="../about-book.html">关于本书</a></li><li class="chapter-item affix "><a href="../into-rust.html">进入 Rust 编程世界</a></li><li class="chapter-item affix "><a href="../first-try/sth-you-should-not-do.html">避免从入门到放弃</a></li><li class="chapter-item affix "><a href="../community.html">社区和锈书</a></li><li class="spacer"></li><li class="chapter-item affix "><a href="../some-thoughts.html">Xobserve: 一切皆可观测</a></li><li class="chapter-item affix "><a href="../beat-ai.html">BeatAI: 工程师 AI 入门圣经</a></li><li class="chapter-item affix "><li class="part-title">Rust 语言基础学习</li><li class="spacer"></li><li class="chapter-item "><a href="../first-try/intro.html"><strong aria-hidden="true">1.</strong> 寻找牛刀，以便小试</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../first-try/installation.html"><strong aria-hidden="true">1.1.</strong> 安装 Rust 环境</a></li><li class="chapter-item "><a href="../first-try/editor.html"><strong aria-hidden="true">1.2.</strong> 墙推 VSCode!</a></li><li class="chapter-item "><a href="../first-try/cargo.html"><strong aria-hidden="true">1.3.</strong> 认识 Cargo</a></li><li class="chapter-item "><a href="../first-try/hello-world.html"><strong aria-hidden="true">1.4.</strong> 不仅仅是 Hello world</a></li><li class="chapter-item "><a href="../first-try/slowly-downloading.html"><strong aria-hidden="true">1.5.</strong> 下载依赖太慢了？</a></li></ol></li><li class="chapter-item "><a href="../basic/intro.html"><strong aria-hidden="true">2.</strong> Rust 基础入门</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../basic/variable.html"><strong aria-hidden="true">2.1.</strong> 变量绑定与解构</a></li><li class="chapter-item "><a href="../basic/base-type/index.html"><strong aria-hidden="true">2.2.</strong> 基本类型</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../basic/base-type/numbers.html"><strong aria-hidden="true">2.2.1.</strong> 数值类型</a></li><li class="chapter-item "><a href="../basic/base-type/char-bool.html"><strong aria-hidden="true">2.2.2.</strong> 字符、布尔、单元类型</a></li><li class="chapter-item "><a href="../basic/base-type/statement-expression.html"><strong aria-hidden="true">2.2.3.</strong> 语句与表达式</a></li><li class="chapter-item "><a href="../basic/base-type/function.html"><strong aria-hidden="true">2.2.4.</strong> 函数</a></li></ol></li><li class="chapter-item "><a href="../basic/ownership/index.html"><strong aria-hidden="true">2.3.</strong> 所有权和借用</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../basic/ownership/ownership.html"><strong aria-hidden="true">2.3.1.</strong> 所有权</a></li><li class="chapter-item "><a href="../basic/ownership/borrowing.html"><strong aria-hidden="true">2.3.2.</strong> 引用与借用</a></li></ol></li><li class="chapter-item "><a href="../basic/compound-type/intro.html"><strong aria-hidden="true">2.4.</strong> 复合类型</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../basic/compound-type/string-slice.html"><strong aria-hidden="true">2.4.1.</strong> 字符串与切片</a></li><li class="chapter-item "><a href="../basic/compound-type/tuple.html"><strong aria-hidden="true">2.4.2.</strong> 元组</a></li><li class="chapter-item "><a href="../basic/compound-type/struct.html"><strong aria-hidden="true">2.4.3.</strong> 结构体</a></li><li class="chapter-item "><a href="../basic/compound-type/enum.html"><strong aria-hidden="true">2.4.4.</strong> 枚举</a></li><li class="chapter-item "><a href="../basic/compound-type/array.html"><strong aria-hidden="true">2.4.5.</strong> 数组</a></li></ol></li><li class="chapter-item "><a href="../basic/flow-control.html"><strong aria-hidden="true">2.5.</strong> 流程控制</a></li><li class="chapter-item "><a href="../basic/match-pattern/intro.html"><strong aria-hidden="true">2.6.</strong> 模式匹配</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../basic/match-pattern/match-if-let.html"><strong aria-hidden="true">2.6.1.</strong> match 和 if let</a></li><li class="chapter-item "><a href="../basic/match-pattern/option.html"><strong aria-hidden="true">2.6.2.</strong> 解构 Option</a></li><li class="chapter-item "><a href="../basic/match-pattern/pattern-match.html"><strong aria-hidden="true">2.6.3.</strong> 模式适用场景</a></li><li class="chapter-item "><a href="../basic/match-pattern/all-patterns.html"><strong aria-hidden="true">2.6.4.</strong> 全模式列表</a></li></ol></li><li class="chapter-item "><a href="../basic/method.html"><strong aria-hidden="true">2.7.</strong> 方法 Method</a></li><li class="chapter-item "><a href="../basic/trait/intro.html"><strong aria-hidden="true">2.8.</strong> 泛型和特征</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../basic/trait/generic.html"><strong aria-hidden="true">2.8.1.</strong> 泛型 Generics</a></li><li class="chapter-item "><a href="../basic/trait/trait.html"><strong aria-hidden="true">2.8.2.</strong> 特征 Trait</a></li><li class="chapter-item "><a href="../basic/trait/trait-object.html"><strong aria-hidden="true">2.8.3.</strong> 特征对象</a></li><li class="chapter-item "><a href="../basic/trait/advance-trait.html"><strong aria-hidden="true">2.8.4.</strong> 进一步深入特征</a></li></ol></li><li class="chapter-item "><a href="../basic/collections/intro.html"><strong aria-hidden="true">2.9.</strong> 集合类型</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../basic/collections/vector.html"><strong aria-hidden="true">2.9.1.</strong> 动态数组 Vector</a></li><li class="chapter-item "><a href="../basic/collections/hashmap.html"><strong aria-hidden="true">2.9.2.</strong> KV 存储 HashMap</a></li></ol></li><li class="chapter-item "><a href="../basic/lifetime.html"><strong aria-hidden="true">2.10.</strong> 认识生命周期</a></li><li class="chapter-item "><a href="../basic/result-error/intro.html"><strong aria-hidden="true">2.11.</strong> 返回值和错误处理</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../basic/result-error/panic.html"><strong aria-hidden="true">2.11.1.</strong> panic! 深入剖析</a></li><li class="chapter-item "><a href="../basic/result-error/result.html"><strong aria-hidden="true">2.11.2.</strong> 返回值 Result 和?</a></li></ol></li><li class="chapter-item "><a href="../basic/crate-module/intro.html"><strong aria-hidden="true">2.12.</strong> 包和模块</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../basic/crate-module/crate.html"><strong aria-hidden="true">2.12.1.</strong> 包 Crate</a></li><li class="chapter-item "><a href="../basic/crate-module/module.html"><strong aria-hidden="true">2.12.2.</strong> 模块 Module</a></li><li class="chapter-item "><a href="../basic/crate-module/use.html"><strong aria-hidden="true">2.12.3.</strong> 使用 use 引入模块及受限可见性</a></li></ol></li><li class="chapter-item "><a href="../basic/comment.html"><strong aria-hidden="true">2.13.</strong> 注释和文档</a></li><li class="chapter-item "><a href="../basic/formatted-output.html"><strong aria-hidden="true">2.14.</strong> 格式化输出</a></li></ol></li><li class="chapter-item "><a href="../basic-practice/intro.html"><strong aria-hidden="true">3.</strong> 入门实战：文件搜索工具</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../basic-practice/base-features.html"><strong aria-hidden="true">3.1.</strong> 基本功能</a></li><li class="chapter-item "><a href="../basic-practice/refactoring.html"><strong aria-hidden="true">3.2.</strong> 增加模块化和错误处理</a></li><li class="chapter-item "><a href="../basic-practice/tests.html"><strong aria-hidden="true">3.3.</strong> 测试驱动开发</a></li><li class="chapter-item "><a href="../basic-practice/envs.html"><strong aria-hidden="true">3.4.</strong> 使用环境变量</a></li><li class="chapter-item "><a href="../basic-practice/stderr.html"><strong aria-hidden="true">3.5.</strong> 重定向错误信息的输出</a></li><li class="chapter-item "><a href="../basic-practice/iterators.html"><strong aria-hidden="true">3.6.</strong> 使用迭代器来改进程序(可选)</a></li></ol></li><li class="chapter-item "><li class="part-title">Rust 语言进阶学习</li><li class="spacer"></li><li class="chapter-item expanded "><a href="../advance/intro.html"><strong aria-hidden="true">4.</strong> Rust 高级进阶</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../advance/lifetime/intro.html"><strong aria-hidden="true">4.1.</strong> 生命周期</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../advance/lifetime/advance.html"><strong aria-hidden="true">4.1.1.</strong> 深入生命周期</a></li><li class="chapter-item "><a href="../advance/lifetime/static.html"><strong aria-hidden="true">4.1.2.</strong> &'static 和 T: 'static</a></li></ol></li><li class="chapter-item "><a href="../advance/functional-programing/intro.html"><strong aria-hidden="true">4.2.</strong> 函数式编程: 闭包、迭代器</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../advance/functional-programing/closure.html"><strong aria-hidden="true">4.2.1.</strong> 闭包 Closure</a></li><li class="chapter-item "><a href="../advance/functional-programing/iterator.html"><strong aria-hidden="true">4.2.2.</strong> 迭代器 Iterator</a></li></ol></li><li class="chapter-item "><a href="../advance/into-types/intro.html"><strong aria-hidden="true">4.3.</strong> 深入类型</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../advance/into-types/converse.html"><strong aria-hidden="true">4.3.1.</strong> 类型转换</a></li><li class="chapter-item "><a href="../advance/into-types/custom-type.html"><strong aria-hidden="true">4.3.2.</strong> newtype 和 类型别名</a></li><li class="chapter-item "><a href="../advance/into-types/sized.html"><strong aria-hidden="true">4.3.3.</strong> Sized 和不定长类型 DST</a></li><li class="chapter-item "><a href="../advance/into-types/enum-int.html"><strong aria-hidden="true">4.3.4.</strong> 枚举和整数</a></li></ol></li><li class="chapter-item "><a href="../advance/smart-pointer/intro.html"><strong aria-hidden="true">4.4.</strong> 智能指针</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../advance/smart-pointer/box.html"><strong aria-hidden="true">4.4.1.</strong> Box堆对象分配</a></li><li class="chapter-item "><a href="../advance/smart-pointer/deref.html"><strong aria-hidden="true">4.4.2.</strong> Deref 解引用</a></li><li class="chapter-item "><a href="../advance/smart-pointer/drop.html"><strong aria-hidden="true">4.4.3.</strong> Drop 释放资源</a></li><li class="chapter-item "><a href="../advance/smart-pointer/rc-arc.html"><strong aria-hidden="true">4.4.4.</strong> Rc 与 Arc 实现 1vN 所有权机制</a></li><li class="chapter-item "><a href="../advance/smart-pointer/cell-refcell.html"><strong aria-hidden="true">4.4.5.</strong> Cell 与 RefCell 内部可变性</a></li></ol></li><li class="chapter-item "><a href="../advance/circle-self-ref/intro.html"><strong aria-hidden="true">4.5.</strong> 循环引用与自引用</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../advance/circle-self-ref/circle-reference.html"><strong aria-hidden="true">4.5.1.</strong> Weak 与循环引用</a></li><li class="chapter-item "><a href="../advance/circle-self-ref/self-referential.html"><strong aria-hidden="true">4.5.2.</strong> 结构体中的自引用</a></li></ol></li><li class="chapter-item "><a href="../advance/concurrency-with-threads/intro.html"><strong aria-hidden="true">4.6.</strong> 多线程并发编程</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../advance/concurrency-with-threads/concurrency-parallelism.html"><strong aria-hidden="true">4.6.1.</strong> 并发和并行</a></li><li class="chapter-item "><a href="../advance/concurrency-with-threads/thread.html"><strong aria-hidden="true">4.6.2.</strong> 使用多线程</a></li><li class="chapter-item "><a href="../advance/concurrency-with-threads/message-passing.html"><strong aria-hidden="true">4.6.3.</strong> 线程同步：消息传递</a></li><li class="chapter-item "><a href="../advance/concurrency-with-threads/sync1.html"><strong aria-hidden="true">4.6.4.</strong> 线程同步：锁、Condvar 和信号量</a></li><li class="chapter-item "><a href="../advance/concurrency-with-threads/sync2.html"><strong aria-hidden="true">4.6.5.</strong> 线程同步：Atomic 原子操作与内存顺序</a></li><li class="chapter-item "><a href="../advance/concurrency-with-threads/send-sync.html"><strong aria-hidden="true">4.6.6.</strong> 基于 Send 和 Sync 的线程安全</a></li></ol></li><li class="chapter-item "><a href="../advance/global-variable.html"><strong aria-hidden="true">4.7.</strong> 全局变量</a></li><li class="chapter-item expanded "><a href="../advance/errors.html" class="active"><strong aria-hidden="true">4.8.</strong> 错误处理</a></li><li class="chapter-item "><a href="../advance/unsafe/intro.html"><strong aria-hidden="true">4.9.</strong> Unsafe Rust</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../advance/unsafe/superpowers.html"><strong aria-hidden="true">4.9.1.</strong> 五种兵器</a></li><li class="chapter-item "><a href="../advance/unsafe/inline-asm.html"><strong aria-hidden="true">4.9.2.</strong> 内联汇编</a></li></ol></li><li class="chapter-item "><a href="../advance/macro.html"><strong aria-hidden="true">4.10.</strong> Macro 宏编程</a></li><li class="chapter-item "><a href="../advance/async/intro.html"><strong aria-hidden="true">4.11.</strong> async/await 异步编程</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../advance/async/getting-started.html"><strong aria-hidden="true">4.11.1.</strong> async 编程入门</a></li><li class="chapter-item "><a href="../advance/async/future-excuting.html"><strong aria-hidden="true">4.11.2.</strong> 底层探秘: Future 执行与任务调度</a></li><li class="chapter-item "><a href="../advance/async/pin-unpin.html"><strong aria-hidden="true">4.11.3.</strong> 定海神针 Pin 和 Unpin</a></li><li class="chapter-item "><a href="../advance/async/async-await.html"><strong aria-hidden="true">4.11.4.</strong> async/await 和 Stream 流处理</a></li><li class="chapter-item "><a href="../advance/async/multi-futures-simultaneous.html"><strong aria-hidden="true">4.11.5.</strong> 同时运行多个 Future</a></li><li class="chapter-item "><a href="../advance/async/pain-points-and-workarounds.html"><strong aria-hidden="true">4.11.6.</strong> 一些疑难问题的解决办法</a></li><li class="chapter-item "><a href="../advance/async/web-server.html"><strong aria-hidden="true">4.11.7.</strong> 实践应用：Async Web 服务器</a></li></ol></li></ol></li><li class="chapter-item "><a href="../advance-practice1/intro.html"><strong aria-hidden="true">5.</strong> 进阶实战1: 实现一个 web 服务器</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../advance-practice1/web-server.html"><strong aria-hidden="true">5.1.</strong> 单线程版本</a></li><li class="chapter-item "><a href="../advance-practice1/multi-threads.html"><strong aria-hidden="true">5.2.</strong> 多线程版本</a></li><li class="chapter-item "><a href="../advance-practice1/graceful-shutdown.html"><strong aria-hidden="true">5.3.</strong> 优雅关闭和资源清理</a></li></ol></li><li class="chapter-item "><a href="../advance-practice/intro.html"><strong aria-hidden="true">6.</strong> 进阶实战2: 实现一个简单 Redis</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../advance-practice/overview.html"><strong aria-hidden="true">6.1.</strong> tokio 概览</a></li><li class="chapter-item "><a href="../advance-practice/getting-startted.html"><strong aria-hidden="true">6.2.</strong> 使用初印象</a></li><li class="chapter-item "><a href="../advance-practice/spawning.html"><strong aria-hidden="true">6.3.</strong> 创建异步任务</a></li><li class="chapter-item "><a href="../advance-practice/shared-state.html"><strong aria-hidden="true">6.4.</strong> 共享状态</a></li><li class="chapter-item "><a href="../advance-practice/channels.html"><strong aria-hidden="true">6.5.</strong> 消息传递</a></li><li class="chapter-item "><a href="../advance-practice/io.html"><strong aria-hidden="true">6.6.</strong> I/O</a></li><li class="chapter-item "><a href="../advance-practice/frame.html"><strong aria-hidden="true">6.7.</strong> 解析数据帧</a></li><li class="chapter-item "><a href="../advance-practice/async.html"><strong aria-hidden="true">6.8.</strong> 深入 async</a></li><li class="chapter-item "><a href="../advance-practice/select.html"><strong aria-hidden="true">6.9.</strong> select</a></li><li class="chapter-item "><a href="../advance-practice/stream.html"><strong aria-hidden="true">6.10.</strong> 类似迭代器的 Stream</a></li><li class="chapter-item "><a href="../advance-practice/graceful-shutdown.html"><strong aria-hidden="true">6.11.</strong> 优雅的关闭</a></li><li class="chapter-item "><a href="../advance-practice/bridging-with-sync.html"><strong aria-hidden="true">6.12.</strong> 异步跟同步共存</a></li></ol></li><li class="chapter-item "><a href="../difficulties/intro.html"><strong aria-hidden="true">7.</strong> Rust 难点攻关</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../difficulties/slice.html"><strong aria-hidden="true">7.1.</strong> 切片和切片引用</a></li><li class="chapter-item "><a href="../difficulties/eq.html"><strong aria-hidden="true">7.2.</strong> Eq 和 PartialEq</a></li><li class="chapter-item "><a href="../difficulties/string.html"><strong aria-hidden="true">7.3.</strong> String、&str 和 str TODO</a></li><li class="chapter-item "><a href="../difficulties/lifetime.html"><strong aria-hidden="true">7.4.</strong> 作用域、生命周期和 NLL TODO</a></li><li class="chapter-item "><a href="../difficulties/move-copy.html"><strong aria-hidden="true">7.5.</strong> move、Copy 和 Clone TODO</a></li><li class="chapter-item "><a href="../advance/difficulties/pointer.html"><strong aria-hidden="true">7.6.</strong> 裸指针、引用和智能指针 TODO</a></li></ol></li><li class="chapter-item "><li class="part-title">常用工具链</li><li class="spacer"></li><li class="chapter-item "><a href="../test/intro.html"><strong aria-hidden="true">8.</strong> 自动化测试</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../test/write-tests.html"><strong aria-hidden="true">8.1.</strong> 编写测试及控制执行</a></li><li class="chapter-item "><a href="../test/unit-integration-test.html"><strong aria-hidden="true">8.2.</strong> 单元测试和集成测试</a></li><li class="chapter-item "><a href="../test/assertion.html"><strong aria-hidden="true">8.3.</strong> 断言 assertion</a></li><li class="chapter-item "><a href="../test/ci.html"><strong aria-hidden="true">8.4.</strong> 用 GitHub Actions 进行持续集成</a></li><li class="chapter-item "><a href="../test/benchmark.html"><strong aria-hidden="true">8.5.</strong> 基准测试 benchmark</a></li></ol></li><li class="chapter-item "><a href="../cargo/intro.html"><strong aria-hidden="true">9.</strong> Cargo 使用指南</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../cargo/getting-started.html"><strong aria-hidden="true">9.1.</strong> 上手使用</a></li><li class="chapter-item "><a href="../cargo/guide/intro.html"><strong aria-hidden="true">9.2.</strong> 基础指南</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../cargo/guide/why-exist.html"><strong aria-hidden="true">9.2.1.</strong> 为何会有 Cargo</a></li><li class="chapter-item "><a href="../cargo/guide/download-package.html"><strong aria-hidden="true">9.2.2.</strong> 下载并构建 Package</a></li><li class="chapter-item "><a href="../cargo/guide/dependencies.html"><strong aria-hidden="true">9.2.3.</strong> 添加依赖</a></li><li class="chapter-item "><a href="../cargo/guide/package-layout.html"><strong aria-hidden="true">9.2.4.</strong> Package 目录结构</a></li><li class="chapter-item "><a href="../cargo/guide/cargo-toml-lock.html"><strong aria-hidden="true">9.2.5.</strong> Cargo.toml vs Cargo.lock</a></li><li class="chapter-item "><a href="../cargo/guide/tests-ci.html"><strong aria-hidden="true">9.2.6.</strong> 测试和 CI</a></li><li class="chapter-item "><a href="../cargo/guide/cargo-cache.html"><strong aria-hidden="true">9.2.7.</strong> Cargo 缓存</a></li><li class="chapter-item "><a href="../cargo/guide/build-cache.html"><strong aria-hidden="true">9.2.8.</strong> Build 缓存</a></li></ol></li><li class="chapter-item "><a href="../cargo/reference/intro.html"><strong aria-hidden="true">9.3.</strong> 进阶指南</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../cargo/reference/specify-deps.html"><strong aria-hidden="true">9.3.1.</strong> 指定依赖项</a></li><li class="chapter-item "><a href="../cargo/reference/deps-overriding.html"><strong aria-hidden="true">9.3.2.</strong> 依赖覆盖</a></li><li class="chapter-item "><a href="../cargo/reference/manifest.html"><strong aria-hidden="true">9.3.3.</strong> Cargo.toml 清单详解</a></li><li class="chapter-item "><a href="../cargo/reference/cargo-target.html"><strong aria-hidden="true">9.3.4.</strong> Cargo Target</a></li><li class="chapter-item "><a href="../cargo/reference/workspaces.html"><strong aria-hidden="true">9.3.5.</strong> 工作空间 Workspace</a></li><li class="chapter-item "><a href="../cargo/reference/features/intro.html"><strong aria-hidden="true">9.3.6.</strong> 条件编译 Features</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../cargo/reference/features/examples.html"><strong aria-hidden="true">9.3.6.1.</strong> Features 示例</a></li></ol></li><li class="chapter-item "><a href="../cargo/reference/profiles.html"><strong aria-hidden="true">9.3.7.</strong> 发布配置 Profile</a></li><li class="chapter-item "><a href="../cargo/reference/configuration.html"><strong aria-hidden="true">9.3.8.</strong> 通过 config.toml 对 Cargo 进行配置</a></li><li class="chapter-item "><a href="../cargo/reference/publishing-on-crates.io.html"><strong aria-hidden="true">9.3.9.</strong> 发布到 crates.io</a></li><li class="chapter-item "><a href="../cargo/reference/build-script/intro.html"><strong aria-hidden="true">9.3.10.</strong> 构建脚本 build.rs</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../cargo/reference/build-script/examples.html"><strong aria-hidden="true">9.3.10.1.</strong> 构建脚本示例</a></li></ol></li></ol></li></ol></li><li class="chapter-item "><li class="part-title">开发实践</li><li class="spacer"></li><li class="chapter-item "><a href="../usecases/intro.html"><strong aria-hidden="true">10.</strong> 企业落地实践</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../usecases/aws-rust.html"><strong aria-hidden="true">10.1.</strong> AWS 为何这么喜欢 Rust?</a></li></ol></li><li class="chapter-item "><a href="../logs/intro.html"><strong aria-hidden="true">11.</strong> 日志和监控</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../logs/about-log.html"><strong aria-hidden="true">11.1.</strong> 日志详解</a></li><li class="chapter-item "><a href="../logs/log.html"><strong aria-hidden="true">11.2.</strong> 日志门面 log</a></li><li class="chapter-item "><a href="../logs/tracing.html"><strong aria-hidden="true">11.3.</strong> 使用 tracing 记录日志</a></li><li class="chapter-item "><a href="../logs/tracing-logger.html"><strong aria-hidden="true">11.4.</strong> 自定义 tracing 的输出格式</a></li><li class="chapter-item "><a href="../logs/observe/intro.html"><strong aria-hidden="true">11.5.</strong> 监控</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../logs/observe/about-observe.html"><strong aria-hidden="true">11.5.1.</strong> 可观测性</a></li><li class="chapter-item "><a href="../logs/observe/trace.html"><strong aria-hidden="true">11.5.2.</strong> 分布式追踪</a></li></ol></li></ol></li><li class="chapter-item "><a href="../practice/intro.html"><strong aria-hidden="true">12.</strong> Rust 最佳实践</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../practice/third-party-libs.html"><strong aria-hidden="true">12.1.</strong> 日常开发三方库精选</a></li><li class="chapter-item "><a href="../practice/naming.html"><strong aria-hidden="true">12.2.</strong> 命名规范</a></li><li class="chapter-item "><a href="../practice/interview.html"><strong aria-hidden="true">12.3.</strong> 面试经验</a></li><li class="chapter-item "><a href="../practice/best-pratice.html"><strong aria-hidden="true">12.4.</strong> 代码开发实践 todo</a></li></ol></li><li class="chapter-item "><a href="../too-many-lists/intro.html"><strong aria-hidden="true">13.</strong> 手把手带你实现链表</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../too-many-lists/do-we-need-it.html"><strong aria-hidden="true">13.1.</strong> 我们到底需不需要链表</a></li><li class="chapter-item "><a href="../too-many-lists/bad-stack/intro.html"><strong aria-hidden="true">13.2.</strong> 不太优秀的单向链表：栈</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../too-many-lists/bad-stack/layout.html"><strong aria-hidden="true">13.2.1.</strong> 数据布局</a></li><li class="chapter-item "><a href="../too-many-lists/bad-stack/basic-operations.html"><strong aria-hidden="true">13.2.2.</strong> 基本操作</a></li><li class="chapter-item "><a href="../too-many-lists/bad-stack/final-code.html"><strong aria-hidden="true">13.2.3.</strong> 最后实现</a></li></ol></li><li class="chapter-item "><a href="../too-many-lists/ok-stack/intro.html"><strong aria-hidden="true">13.3.</strong> 还可以的单向链表</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../too-many-lists/ok-stack/type-optimizing.html"><strong aria-hidden="true">13.3.1.</strong> 优化类型定义</a></li><li class="chapter-item "><a href="../too-many-lists/ok-stack/peek.html"><strong aria-hidden="true">13.3.2.</strong> 定义 Peek 函数</a></li><li class="chapter-item "><a href="../too-many-lists/ok-stack/iter.html"><strong aria-hidden="true">13.3.3.</strong> IntoIter 和 Iter</a></li><li class="chapter-item "><a href="../too-many-lists/ok-stack/itermut.html"><strong aria-hidden="true">13.3.4.</strong> IterMut 以及完整代码</a></li></ol></li><li class="chapter-item "><a href="../too-many-lists/persistent-stack/intro.html"><strong aria-hidden="true">13.4.</strong> 持久化单向链表</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../too-many-lists/persistent-stack/layout.html"><strong aria-hidden="true">13.4.1.</strong> 数据布局和基本操作</a></li><li class="chapter-item "><a href="../too-many-lists/persistent-stack/drop-arc.html"><strong aria-hidden="true">13.4.2.</strong> Drop、Arc 及完整代码</a></li></ol></li><li class="chapter-item "><a href="../too-many-lists/deque/intro.html"><strong aria-hidden="true">13.5.</strong> 不咋样的双端队列</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../too-many-lists/deque/layout.html"><strong aria-hidden="true">13.5.1.</strong> 数据布局和基本操作</a></li><li class="chapter-item "><a href="../too-many-lists/deque/peek.html"><strong aria-hidden="true">13.5.2.</strong> Peek</a></li><li class="chapter-item "><a href="../too-many-lists/deque/symmetric.html"><strong aria-hidden="true">13.5.3.</strong> 基本操作的对称镜像</a></li><li class="chapter-item "><a href="../too-many-lists/deque/iterator.html"><strong aria-hidden="true">13.5.4.</strong> 迭代器</a></li><li class="chapter-item "><a href="../too-many-lists/deque/final-code.html"><strong aria-hidden="true">13.5.5.</strong> 最终代码</a></li></ol></li><li class="chapter-item "><a href="../too-many-lists/unsafe-queue/intro.html"><strong aria-hidden="true">13.6.</strong> 不错的 unsafe 队列</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../too-many-lists/unsafe-queue/layout.html"><strong aria-hidden="true">13.6.1.</strong> 数据布局</a></li><li class="chapter-item "><a href="../too-many-lists/unsafe-queue/basics.html"><strong aria-hidden="true">13.6.2.</strong> 基本操作</a></li><li class="chapter-item "><a href="../too-many-lists/unsafe-queue/miri.html"><strong aria-hidden="true">13.6.3.</strong> Miri</a></li><li class="chapter-item "><a href="../too-many-lists/unsafe-queue/stacked-borrow.html"><strong aria-hidden="true">13.6.4.</strong> 栈借用</a></li><li class="chapter-item "><a href="../too-many-lists/unsafe-queue/testing-stacked-borrow.html"><strong aria-hidden="true">13.6.5.</strong> 测试栈借用</a></li><li class="chapter-item "><a href="../too-many-lists/unsafe-queue/layout2.html"><strong aria-hidden="true">13.6.6.</strong> 数据布局 2</a></li><li class="chapter-item "><a href="../too-many-lists/unsafe-queue/extra-junk.html"><strong aria-hidden="true">13.6.7.</strong> 额外的操作</a></li><li class="chapter-item "><a href="../too-many-lists/unsafe-queue/final-code.html"><strong aria-hidden="true">13.6.8.</strong> 最终代码</a></li></ol></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/intro.html"><strong aria-hidden="true">13.7.</strong> 生产级的双向 unsafe 队列</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/layout.html"><strong aria-hidden="true">13.7.1.</strong> 数据布局</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/variance-and-phantomData.html"><strong aria-hidden="true">13.7.2.</strong> 型变与子类型</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/basics.html"><strong aria-hidden="true">13.7.3.</strong> 基础结构</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/drop-and-panic-safety.html"><strong aria-hidden="true">13.7.4.</strong> 恐慌与安全</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/boring-combinatorics.html"><strong aria-hidden="true">13.7.5.</strong> 无聊的组合</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/filling-in-random-bits.html"><strong aria-hidden="true">13.7.6.</strong> 其它特征</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/testing.html"><strong aria-hidden="true">13.7.7.</strong> 测试</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/send-sync-and-compile-tests.html"><strong aria-hidden="true">13.7.8.</strong> Send,Sync和编译测试</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/implementing-cursors.html"><strong aria-hidden="true">13.7.9.</strong> 实现游标</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/testing-cursors.html"><strong aria-hidden="true">13.7.10.</strong> 测试游标</a></li><li class="chapter-item "><a href="../too-many-lists/production-unsafe-deque/final-code.html"><strong aria-hidden="true">13.7.11.</strong> 最终代码</a></li></ol></li><li class="chapter-item "><a href="../too-many-lists/advanced-lists/intro.html"><strong aria-hidden="true">13.8.</strong> 使用高级技巧实现链表</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../too-many-lists/advanced-lists/double-singly.html"><strong aria-hidden="true">13.8.1.</strong> 双单向链表</a></li><li class="chapter-item "><a href="../too-many-lists/advanced-lists/stack-allocated.html"><strong aria-hidden="true">13.8.2.</strong> 栈上的链表</a></li></ol></li></ol></li><li class="chapter-item "><li class="part-title">攻克编译错误</li><li class="spacer"></li><li class="chapter-item "><a href="../compiler/intro.html"><strong aria-hidden="true">14.</strong> 征服编译错误</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../compiler/fight-with-compiler/intro.html"><strong aria-hidden="true">14.1.</strong> 对抗编译检查</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../compiler/fight-with-compiler/lifetime/intro.html"><strong aria-hidden="true">14.1.1.</strong> 生命周期</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../compiler/fight-with-compiler/lifetime/too-long1.html"><strong aria-hidden="true">14.1.1.1.</strong> 生命周期过大-01</a></li><li class="chapter-item "><a href="../compiler/fight-with-compiler/lifetime/too-long2.html"><strong aria-hidden="true">14.1.1.2.</strong> 生命周期过大-02</a></li><li class="chapter-item "><a href="../compiler/fight-with-compiler/lifetime/loop.html"><strong aria-hidden="true">14.1.1.3.</strong> 循环中的生命周期</a></li><li class="chapter-item "><a href="../compiler/fight-with-compiler/lifetime/closure-with-static.html"><strong aria-hidden="true">14.1.1.4.</strong> 闭包碰到特征对象-01</a></li></ol></li><li class="chapter-item "><a href="../compiler/fight-with-compiler/borrowing/intro.html"><strong aria-hidden="true">14.1.2.</strong> 重复借用</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../compiler/fight-with-compiler/borrowing/ref-exist-in-out-fn.html"><strong aria-hidden="true">14.1.2.1.</strong> 同时在函数内外使用引用</a></li><li class="chapter-item "><a href="../compiler/fight-with-compiler/borrowing/borrow-distinct-fields-of-struct.html"><strong aria-hidden="true">14.1.2.2.</strong> 智能指针引起的重复借用错误</a></li></ol></li><li class="chapter-item "><a href="../compiler/fight-with-compiler/unconstrained.html"><strong aria-hidden="true">14.1.3.</strong> 类型未限制(todo)</a></li><li class="chapter-item "><a href="../compiler/fight-with-compiler/phantom-data.html"><strong aria-hidden="true">14.1.4.</strong> 幽灵数据(todo)</a></li></ol></li><li class="chapter-item "><a href="../compiler/pitfalls/index.html"><strong aria-hidden="true">14.2.</strong> Rust 常见陷阱</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../compiler/pitfalls/use-vec-in-for.html"><strong aria-hidden="true">14.2.1.</strong> for 循环中使用外部数组</a></li><li class="chapter-item "><a href="../compiler/pitfalls/stack-overflow.html"><strong aria-hidden="true">14.2.2.</strong> 线程类型导致的栈溢出</a></li><li class="chapter-item "><a href="../compiler/pitfalls/arithmetic-overflow.html"><strong aria-hidden="true">14.2.3.</strong> 算术溢出导致的 panic</a></li><li class="chapter-item "><a href="../compiler/pitfalls/closure-with-lifetime.html"><strong aria-hidden="true">14.2.4.</strong> 闭包中奇怪的生命周期</a></li><li class="chapter-item "><a href="../compiler/pitfalls/the-disabled-mutability.html"><strong aria-hidden="true">14.2.5.</strong> 可变变量不可变？</a></li><li class="chapter-item "><a href="../compiler/pitfalls/multiple-mutable-references.html"><strong aria-hidden="true">14.2.6.</strong> 可变借用失败引发的深入思考</a></li><li class="chapter-item "><a href="../compiler/pitfalls/lazy-iterators.html"><strong aria-hidden="true">14.2.7.</strong> 不太勤快的迭代器</a></li><li class="chapter-item "><a href="../compiler/pitfalls/weird-ranges.html"><strong aria-hidden="true">14.2.8.</strong> 奇怪的序列 x..y</a></li><li class="chapter-item "><a href="../compiler/pitfalls/iterator-everywhere.html"><strong aria-hidden="true">14.2.9.</strong> 无处不在的迭代器</a></li><li class="chapter-item "><a href="../compiler/pitfalls/main-with-channel-blocked.html"><strong aria-hidden="true">14.2.10.</strong> 线程间传递消息导致主线程无法结束</a></li><li class="chapter-item "><a href="../compiler/pitfalls/utf8-performance.html"><strong aria-hidden="true">14.2.11.</strong> 警惕 UTF-8 引发的性能隐患</a></li></ol></li></ol></li><li class="chapter-item "><li class="part-title">性能优化</li><li class="spacer"></li><li class="chapter-item "><a href="../profiling/intro.html"><strong aria-hidden="true">15.</strong> Rust 性能优化 todo</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../profiling/memory/intro.html"><strong aria-hidden="true">15.1.</strong> 深入内存 todo</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../profiling/memory/pointer-ref.html"><strong aria-hidden="true">15.1.1.</strong> 指针和引用 todo</a></li><li class="chapter-item "><a href="../profiling/memory/uninit.html"><strong aria-hidden="true">15.1.2.</strong> 未初始化内存 todo</a></li><li class="chapter-item "><a href="../profiling/memory/allocation.html"><strong aria-hidden="true">15.1.3.</strong> 内存分配 todo</a></li><li class="chapter-item "><a href="../profiling/memory/layout.html"><strong aria-hidden="true">15.1.4.</strong> 内存布局 todo</a></li><li class="chapter-item "><a href="../profiling/memory/virtual.html"><strong aria-hidden="true">15.1.5.</strong> 虚拟内存 todo</a></li></ol></li><li class="chapter-item "><a href="../profiling/performance/intro.html"><strong aria-hidden="true">15.2.</strong> 性能调优 doing</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../profiling/performance/string.html"><strong aria-hidden="true">15.2.1.</strong> 字符串操作性能</a></li><li class="chapter-item "><a href="../profiling/performance/deep-into-move.html"><strong aria-hidden="true">15.2.2.</strong> 深入理解 move</a></li><li class="chapter-item "><a href="../profiling/performance/early-optimise.html"><strong aria-hidden="true">15.2.3.</strong> 糟糕的提前优化 todo</a></li><li class="chapter-item "><a href="../profiling/performance/clone-copy.html"><strong aria-hidden="true">15.2.4.</strong> Clone 和 Copy todo</a></li><li class="chapter-item "><a href="../profiling/performance/runtime-check.html"><strong aria-hidden="true">15.2.5.</strong> 减少 Runtime check(todo)</a></li><li class="chapter-item "><a href="../profiling/performance/cpu-cache.html"><strong aria-hidden="true">15.2.6.</strong> CPU 缓存性能优化 todo</a></li><li class="chapter-item "><a href="../profiling/performance/calculate.html"><strong aria-hidden="true">15.2.7.</strong> 计算性能优化 todo</a></li><li class="chapter-item "><a href="../profiling/performance/heap-stack.html"><strong aria-hidden="true">15.2.8.</strong> 堆和栈 todo</a></li><li class="chapter-item "><a href="../profiling/performance/allocator.html"><strong aria-hidden="true">15.2.9.</strong> 内存 allocator todo</a></li><li class="chapter-item "><a href="../profiling/performance/tools.html"><strong aria-hidden="true">15.2.10.</strong> 常用性能测试工具 todo</a></li><li class="chapter-item "><a href="../profiling/performance/enum.html"><strong aria-hidden="true">15.2.11.</strong> Enum 内存优化 todo</a></li></ol></li><li class="chapter-item "><a href="../profiling/compiler/intro.html"><strong aria-hidden="true">15.3.</strong> 编译优化 todo</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../profiling/compiler/llvm.html"><strong aria-hidden="true">15.3.1.</strong> LLVM todo</a></li><li class="chapter-item "><a href="../profiling/compiler/attributes.html"><strong aria-hidden="true">15.3.2.</strong> 常见属性标记 todo</a></li><li class="chapter-item "><a href="../profiling/compiler/speed-up.html"><strong aria-hidden="true">15.3.3.</strong> 提升编译速度 todo</a></li><li class="chapter-item "><a href="../profiling/compiler/optimization/intro.html"><strong aria-hidden="true">15.3.4.</strong> 编译器优化 todo</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../profiling/compiler/optimization/option.html"><strong aria-hidden="true">15.3.4.1.</strong> Option 枚举 todo</a></li></ol></li></ol></li></ol></li><li class="chapter-item "><li class="part-title">附录</li><li class="spacer"></li><li class="chapter-item "><div><strong aria-hidden="true">16.</strong> Appendix</div><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../appendix/keywords.html"><strong aria-hidden="true">16.1.</strong> 关键字</a></li><li class="chapter-item "><a href="../appendix/operators.html"><strong aria-hidden="true">16.2.</strong> 运算符与符号</a></li><li class="chapter-item "><a href="../appendix/expressions.html"><strong aria-hidden="true">16.3.</strong> 表达式</a></li><li class="chapter-item "><a href="../appendix/derive.html"><strong aria-hidden="true">16.4.</strong> 派生特征 trait</a></li><li class="chapter-item "><a href="../appendix/prelude.html"><strong aria-hidden="true">16.5.</strong> prelude 模块 todo</a></li><li class="chapter-item "><a href="../appendix/rust-version.html"><strong aria-hidden="true">16.6.</strong> Rust 版本说明</a></li><li class="chapter-item "><a href="../appendix/rust-versions/intro.html"><strong aria-hidden="true">16.7.</strong> Rust 历次版本更新解读</a><a class="toggle"><div>❱</div></a></li><li><ol class="section"><li class="chapter-item "><a href="../appendix/rust-versions/1.58.html"><strong aria-hidden="true">16.7.1.</strong> 1.58</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.59.html"><strong aria-hidden="true">16.7.2.</strong> 1.59</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.60.html"><strong aria-hidden="true">16.7.3.</strong> 1.60</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.61.html"><strong aria-hidden="true">16.7.4.</strong> 1.61</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.62.html"><strong aria-hidden="true">16.7.5.</strong> 1.62</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.63.html"><strong aria-hidden="true">16.7.6.</strong> 1.63</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.64.html"><strong aria-hidden="true">16.7.7.</strong> 1.64</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.65.html"><strong aria-hidden="true">16.7.8.</strong> 1.65</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.66.html"><strong aria-hidden="true">16.7.9.</strong> 1.66</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.67.html"><strong aria-hidden="true">16.7.10.</strong> 1.67</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.68.html"><strong aria-hidden="true">16.7.11.</strong> 1.68</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.69.html"><strong aria-hidden="true">16.7.12.</strong> 1.69</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.70.html"><strong aria-hidden="true">16.7.13.</strong> 1.70</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.71.html"><strong aria-hidden="true">16.7.14.</strong> 1.71</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.72.html"><strong aria-hidden="true">16.7.15.</strong> 1.72</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.73.html"><strong aria-hidden="true">16.7.16.</strong> 1.73</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.74.html"><strong aria-hidden="true">16.7.17.</strong> 1.74</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.75.html"><strong aria-hidden="true">16.7.18.</strong> 1.75</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.76.html"><strong aria-hidden="true">16.7.19.</strong> 1.76</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.77.html"><strong aria-hidden="true">16.7.20.</strong> 1.77</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.78.html"><strong aria-hidden="true">16.7.21.</strong> 1.78</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.79.html"><strong aria-hidden="true">16.7.22.</strong> 1.79</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.80.html"><strong aria-hidden="true">16.7.23.</strong> 1.80</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.81.html"><strong aria-hidden="true">16.7.24.</strong> 1.81</a></li><li class="chapter-item "><a href="../appendix/rust-versions/1.82.html"><strong aria-hidden="true">16.7.25.</strong> 1.82</a></li></ol></li></ol></li></ol>
|
|
|
</div>
|
|
|
<div id="sidebar-resize-handle" class="sidebar-resize-handle">
|
|
|
<div class="sidebar-resize-indicator"></div>
|
|
|
</div>
|
|
|
</nav>
|
|
|
|
|
|
<!-- Track and set sidebar scroll position -->
|
|
|
<script>
|
|
|
var sidebarScrollbox = document.querySelector('#sidebar .sidebar-scrollbox');
|
|
|
sidebarScrollbox.addEventListener('click', function(e) {
|
|
|
if (e.target.tagName === 'A') {
|
|
|
sessionStorage.setItem('sidebar-scroll', sidebarScrollbox.scrollTop);
|
|
|
}
|
|
|
}, { passive: true });
|
|
|
var sidebarScrollTop = sessionStorage.getItem('sidebar-scroll');
|
|
|
sessionStorage.removeItem('sidebar-scroll');
|
|
|
if (sidebarScrollTop) {
|
|
|
// preserve sidebar scroll position when navigating via links within sidebar
|
|
|
sidebarScrollbox.scrollTop = sidebarScrollTop;
|
|
|
} else {
|
|
|
// scroll sidebar to current active section when navigating via "next/previous chapter" buttons
|
|
|
var activeSection = document.querySelector('#sidebar .active');
|
|
|
if (activeSection) {
|
|
|
activeSection.scrollIntoView({ block: 'center' });
|
|
|
}
|
|
|
}
|
|
|
</script>
|
|
|
|
|
|
<div id="page-wrapper" class="page-wrapper">
|
|
|
|
|
|
<div class="page">
|
|
|
<div id="menu-bar-hover-placeholder"></div>
|
|
|
<div id="menu-bar" class="menu-bar sticky">
|
|
|
<div class="left-buttons">
|
|
|
<label id="sidebar-toggle" class="icon-button" for="sidebar-toggle-anchor" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
|
|
|
<i class="fa fa-bars"></i>
|
|
|
</label>
|
|
|
<button id="theme-toggle" class="icon-button" type="button" title="Change theme" aria-label="Change theme" aria-haspopup="true" aria-expanded="false" aria-controls="theme-list">
|
|
|
<i class="fa fa-paint-brush"></i>
|
|
|
</button>
|
|
|
<ul id="theme-list" class="theme-popup" aria-label="Themes" role="menu">
|
|
|
<li role="none"><button role="menuitem" class="theme" id="light">Light</button></li>
|
|
|
<li role="none"><button role="menuitem" class="theme" id="rust">Rust</button></li>
|
|
|
<li role="none"><button role="menuitem" class="theme" id="coal">Coal</button></li>
|
|
|
<li role="none"><button role="menuitem" class="theme" id="navy">Navy</button></li>
|
|
|
<li role="none"><button role="menuitem" class="theme" id="ayu">Ayu</button></li>
|
|
|
</ul>
|
|
|
<button id="search-toggle" class="icon-button" type="button" title="Search. (Shortkey: s)" aria-label="Toggle Searchbar" aria-expanded="false" aria-keyshortcuts="S" aria-controls="searchbar">
|
|
|
<i class="fa fa-search"></i>
|
|
|
</button>
|
|
|
</div>
|
|
|
|
|
|
<h1 class="menu-title">Rust语言圣经(Rust Course)</h1>
|
|
|
|
|
|
<div class="right-buttons">
|
|
|
<a href="../print.html" title="Print this book" aria-label="Print this book">
|
|
|
<i id="print-button" class="fa fa-print"></i>
|
|
|
</a>
|
|
|
<a href="https://github.com/sunface/rust-course" title="Git repository" aria-label="Git repository">
|
|
|
<i id="git-repository-button" class="fa fa-github"></i>
|
|
|
</a>
|
|
|
<a href="https://github.com/sunface/rust-course/edit/main/src/advance/errors.md" title="Suggest an edit" aria-label="Suggest an edit">
|
|
|
<i id="git-edit-button" class="fa fa-edit"></i>
|
|
|
</a>
|
|
|
|
|
|
</div>
|
|
|
</div>
|
|
|
|
|
|
<div id="search-wrapper" class="hidden">
|
|
|
<form id="searchbar-outer" class="searchbar-outer">
|
|
|
<input type="search" id="searchbar" name="searchbar" placeholder="Search this book ..." aria-controls="searchresults-outer" aria-describedby="searchresults-header">
|
|
|
</form>
|
|
|
<div id="searchresults-outer" class="searchresults-outer hidden">
|
|
|
<div id="searchresults-header" class="searchresults-header"></div>
|
|
|
<ul id="searchresults">
|
|
|
</ul>
|
|
|
</div>
|
|
|
</div>
|
|
|
|
|
|
<!-- Apply ARIA attributes after the sidebar and the sidebar toggle button are added to the DOM -->
|
|
|
<script>
|
|
|
document.getElementById('sidebar-toggle').setAttribute('aria-expanded', sidebar === 'visible');
|
|
|
document.getElementById('sidebar').setAttribute('aria-hidden', sidebar !== 'visible');
|
|
|
Array.from(document.querySelectorAll('#sidebar a')).forEach(function(link) {
|
|
|
link.setAttribute('tabIndex', sidebar === 'visible' ? 0 : -1);
|
|
|
});
|
|
|
</script>
|
|
|
|
|
|
<div id="content" class="content">
|
|
|
<!-- Page table of contents -->
|
|
|
<div class="sidetoc"><nav class="pagetoc"></nav></div>
|
|
|
<main>
|
|
|
<h1 id="错误处理"><a class="header" href="#错误处理">错误处理</a></h1>
|
|
|
<p>在之前的<a href="https://course.rs/basic/result-error/intro.html">返回值和错误处理</a>章节中，我们学习了几个重要的概念，例如 <code>Result</code> 用于返回结果处理，<code>?</code> 用于错误的传播，若大家对此还较为模糊，强烈建议回头温习下。</p>
|
|
|
<p>在本章节中一起来看看如何对 <code>Result</code> ( <code>Option</code> ) 做进一步的处理，以及如何定义自己的错误类型。</p>
|
|
|
<h2 id="组合器"><a class="header" href="#组合器">组合器</a></h2>
|
|
|
<p>在设计模式中，有一个组合器模式，相信有 Java 背景的同学对此并不陌生。</p>
|
|
|
<blockquote>
|
|
|
<p>将对象组合成树形结构以表示“部分整体”的层次结构。组合模式使得用户对单个对象和组合对象的使用具有一致性。–GoF <<设计模式>></p>
|
|
|
</blockquote>
|
|
|
<p>与组合器模式有所不同，在 Rust 中，组合器更多的是用于对返回结果的类型进行变换：例如使用 <code>ok_or</code> 将一个 <code>Option</code> 类型转换成 <code>Result</code> 类型。</p>
|
|
|
<p>下面我们来看看一些常见的组合器。</p>
|
|
|
<h4 id="or-和-and"><a class="header" href="#or-和-and">or() 和 and()</a></h4>
|
|
|
<p>跟布尔关系的与/或很像，这两个方法会对两个表达式做逻辑组合，最终返回 <code>Option</code> / <code>Result</code>。</p>
|
|
|
<ul>
|
|
|
<li><code>or()</code>，表达式按照顺序求值，若任何一个表达式的结果是 <code>Some</code> 或 <code>Ok</code>，则该值会立刻返回</li>
|
|
|
<li><code>and()</code>，若两个表达式的结果都是 <code>Some</code> 或 <code>Ok</code>，则<strong>第二个表达式中的值被返回</strong>。若任何一个的结果是 <code>None</code> 或 <code>Err</code> ，则立刻返回。</li>
|
|
|
</ul>
|
|
|
<p>实际上，只要将布尔表达式的 <code>true</code> / <code>false</code>，替换成 <code>Some</code> / <code>None</code> 或 <code>Ok</code> / <code>Err</code> 就很好理解了。</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">fn main() {
|
|
|
let s1 = Some("some1");
|
|
|
let s2 = Some("some2");
|
|
|
let n: Option<&str> = None;
|
|
|
|
|
|
let o1: Result<&str, &str> = Ok("ok1");
|
|
|
let o2: Result<&str, &str> = Ok("ok2");
|
|
|
let e1: Result<&str, &str> = Err("error1");
|
|
|
let e2: Result<&str, &str> = Err("error2");
|
|
|
|
|
|
assert_eq!(s1.or(s2), s1); // Some1 or Some2 = Some1
|
|
|
assert_eq!(s1.or(n), s1); // Some or None = Some
|
|
|
assert_eq!(n.or(s1), s1); // None or Some = Some
|
|
|
assert_eq!(n.or(n), n); // None1 or None2 = None2
|
|
|
|
|
|
assert_eq!(o1.or(o2), o1); // Ok1 or Ok2 = Ok1
|
|
|
assert_eq!(o1.or(e1), o1); // Ok or Err = Ok
|
|
|
assert_eq!(e1.or(o1), o1); // Err or Ok = Ok
|
|
|
assert_eq!(e1.or(e2), e2); // Err1 or Err2 = Err2
|
|
|
|
|
|
assert_eq!(s1.and(s2), s2); // Some1 and Some2 = Some2
|
|
|
assert_eq!(s1.and(n), n); // Some and None = None
|
|
|
assert_eq!(n.and(s1), n); // None and Some = None
|
|
|
assert_eq!(n.and(n), n); // None1 and None2 = None1
|
|
|
|
|
|
assert_eq!(o1.and(o2), o2); // Ok1 and Ok2 = Ok2
|
|
|
assert_eq!(o1.and(e1), e1); // Ok and Err = Err
|
|
|
assert_eq!(e1.and(o1), e1); // Err and Ok = Err
|
|
|
assert_eq!(e1.and(e2), e1); // Err1 and Err2 = Err1
|
|
|
}</code></pre></pre>
|
|
|
<p>除了 <code>or</code> 和 <code>and</code> 之外，Rust 还为我们提供了 <code>xor</code> ，但是它只能应用在 <code>Option</code> 上，其实想想也是这个理，如果能应用在 <code>Result</code> 上，那你又该如何对一个值和错误进行异或操作？</p>
|
|
|
<h4 id="or_else-和-and_then"><a class="header" href="#or_else-和-and_then">or_else() 和 and_then()</a></h4>
|
|
|
<p>它们跟 <code>or()</code> 和 <code>and()</code> 类似，唯一的区别在于，它们的第二个表达式是一个闭包。</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">fn main() {
|
|
|
// or_else with Option
|
|
|
let s1 = Some("some1");
|
|
|
let s2 = Some("some2");
|
|
|
let fn_some = || Some("some2"); // 类似于: let fn_some = || -> Option<&str> { Some("some2") };
|
|
|
|
|
|
let n: Option<&str> = None;
|
|
|
let fn_none = || None;
|
|
|
|
|
|
assert_eq!(s1.or_else(fn_some), s1); // Some1 or_else Some2 = Some1
|
|
|
assert_eq!(s1.or_else(fn_none), s1); // Some or_else None = Some
|
|
|
assert_eq!(n.or_else(fn_some), s2); // None or_else Some = Some
|
|
|
assert_eq!(n.or_else(fn_none), None); // None1 or_else None2 = None2
|
|
|
|
|
|
// or_else with Result
|
|
|
let o1: Result<&str, &str> = Ok("ok1");
|
|
|
let o2: Result<&str, &str> = Ok("ok2");
|
|
|
let fn_ok = |_| Ok("ok2"); // 类似于: let fn_ok = |_| -> Result<&str, &str> { Ok("ok2") };
|
|
|
|
|
|
let e1: Result<&str, &str> = Err("error1");
|
|
|
let e2: Result<&str, &str> = Err("error2");
|
|
|
let fn_err = |_| Err("error2");
|
|
|
|
|
|
assert_eq!(o1.or_else(fn_ok), o1); // Ok1 or_else Ok2 = Ok1
|
|
|
assert_eq!(o1.or_else(fn_err), o1); // Ok or_else Err = Ok
|
|
|
assert_eq!(e1.or_else(fn_ok), o2); // Err or_else Ok = Ok
|
|
|
assert_eq!(e1.or_else(fn_err), e2); // Err1 or_else Err2 = Err2
|
|
|
}</code></pre></pre>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">fn main() {
|
|
|
// and_then with Option
|
|
|
let s1 = Some("some1");
|
|
|
let s2 = Some("some2");
|
|
|
let fn_some = |_| Some("some2"); // 类似于: let fn_some = |_| -> Option<&str> { Some("some2") };
|
|
|
|
|
|
let n: Option<&str> = None;
|
|
|
let fn_none = |_| None;
|
|
|
|
|
|
assert_eq!(s1.and_then(fn_some), s2); // Some1 and_then Some2 = Some2
|
|
|
assert_eq!(s1.and_then(fn_none), n); // Some and_then None = None
|
|
|
assert_eq!(n.and_then(fn_some), n); // None and_then Some = None
|
|
|
assert_eq!(n.and_then(fn_none), n); // None1 and_then None2 = None1
|
|
|
|
|
|
// and_then with Result
|
|
|
let o1: Result<&str, &str> = Ok("ok1");
|
|
|
let o2: Result<&str, &str> = Ok("ok2");
|
|
|
let fn_ok = |_| Ok("ok2"); // 类似于: let fn_ok = |_| -> Result<&str, &str> { Ok("ok2") };
|
|
|
|
|
|
let e1: Result<&str, &str> = Err("error1");
|
|
|
let e2: Result<&str, &str> = Err("error2");
|
|
|
let fn_err = |_| Err("error2");
|
|
|
|
|
|
assert_eq!(o1.and_then(fn_ok), o2); // Ok1 and_then Ok2 = Ok2
|
|
|
assert_eq!(o1.and_then(fn_err), e2); // Ok and_then Err = Err
|
|
|
assert_eq!(e1.and_then(fn_ok), e1); // Err and_then Ok = Err
|
|
|
assert_eq!(e1.and_then(fn_err), e1); // Err1 and_then Err2 = Err1
|
|
|
}</code></pre></pre>
|
|
|
<h4 id="filter"><a class="header" href="#filter">filter</a></h4>
|
|
|
<p><code>filter</code> 用于对 <code>Option</code> 进行过滤：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">fn main() {
|
|
|
let s1 = Some(3);
|
|
|
let s2 = Some(6);
|
|
|
let n = None;
|
|
|
|
|
|
let fn_is_even = |x: &i8| x % 2 == 0;
|
|
|
|
|
|
assert_eq!(s1.filter(fn_is_even), n); // Some(3) -> 3 is not even -> None
|
|
|
assert_eq!(s2.filter(fn_is_even), s2); // Some(6) -> 6 is even -> Some(6)
|
|
|
assert_eq!(n.filter(fn_is_even), n); // None -> no value -> None
|
|
|
}</code></pre></pre>
|
|
|
<h4 id="map-和-map_err"><a class="header" href="#map-和-map_err">map() 和 map_err()</a></h4>
|
|
|
<p><code>map</code> 可以将 <code>Some</code> 或 <code>Ok</code> 中的值映射为另一个：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">fn main() {
|
|
|
let s1 = Some("abcde");
|
|
|
let s2 = Some(5);
|
|
|
|
|
|
let n1: Option<&str> = None;
|
|
|
let n2: Option<usize> = None;
|
|
|
|
|
|
let o1: Result<&str, &str> = Ok("abcde");
|
|
|
let o2: Result<usize, &str> = Ok(5);
|
|
|
|
|
|
let e1: Result<&str, &str> = Err("abcde");
|
|
|
let e2: Result<usize, &str> = Err("abcde");
|
|
|
|
|
|
let fn_character_count = |s: &str| s.chars().count();
|
|
|
|
|
|
assert_eq!(s1.map(fn_character_count), s2); // Some1 map = Some2
|
|
|
assert_eq!(n1.map(fn_character_count), n2); // None1 map = None2
|
|
|
|
|
|
assert_eq!(o1.map(fn_character_count), o2); // Ok1 map = Ok2
|
|
|
assert_eq!(e1.map(fn_character_count), e2); // Err1 map = Err2
|
|
|
}</code></pre></pre>
|
|
|
<p>但是如果你想要将 <code>Err</code> 中的值进行改变， <code>map</code> 就无能为力了，此时我们需要用 <code>map_err</code>：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">fn main() {
|
|
|
let o1: Result<&str, &str> = Ok("abcde");
|
|
|
let o2: Result<&str, isize> = Ok("abcde");
|
|
|
|
|
|
let e1: Result<&str, &str> = Err("404");
|
|
|
let e2: Result<&str, isize> = Err(404);
|
|
|
|
|
|
let fn_character_count = |s: &str| -> isize { s.parse().unwrap() }; // 该函数返回一个 isize
|
|
|
|
|
|
assert_eq!(o1.map_err(fn_character_count), o2); // Ok1 map = Ok2
|
|
|
assert_eq!(e1.map_err(fn_character_count), e2); // Err1 map = Err2
|
|
|
}</code></pre></pre>
|
|
|
<p>通过对 <code>o1</code> 的操作可以看出，与 <code>map</code> 面对 <code>Err</code> 时的短小类似， <code>map_err</code> 面对 <code>Ok</code> 时也是相当无力的。</p>
|
|
|
<h4 id="map_or-和-map_or_else"><a class="header" href="#map_or-和-map_or_else">map_or() 和 map_or_else()</a></h4>
|
|
|
<p><code>map_or</code> 在 <code>map</code> 的基础上提供了一个默认值:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">fn main() {
|
|
|
const V_DEFAULT: u32 = 1;
|
|
|
|
|
|
let s: Result<u32, ()> = Ok(10);
|
|
|
let n: Option<u32> = None;
|
|
|
let fn_closure = |v: u32| v + 2;
|
|
|
|
|
|
assert_eq!(s.map_or(V_DEFAULT, fn_closure), 12);
|
|
|
assert_eq!(n.map_or(V_DEFAULT, fn_closure), V_DEFAULT);
|
|
|
}</code></pre></pre>
|
|
|
<p>如上所示，当处理 <code>None</code> 的时候，<code>V_DEFAULT</code> 作为默认值被直接返回。</p>
|
|
|
<p><code>map_or_else</code> 与 <code>map_or</code> 类似，但是它是通过一个闭包来提供默认值:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">fn main() {
|
|
|
let s = Some(10);
|
|
|
let n: Option<i8> = None;
|
|
|
|
|
|
let fn_closure = |v: i8| v + 2;
|
|
|
let fn_default = || 1;
|
|
|
|
|
|
assert_eq!(s.map_or_else(fn_default, fn_closure), 12);
|
|
|
assert_eq!(n.map_or_else(fn_default, fn_closure), 1);
|
|
|
|
|
|
let o = Ok(10);
|
|
|
let e = Err(5);
|
|
|
let fn_default_for_result = |v: i8| v + 1; // 闭包可以对 Err 中的值进行处理，并返回一个新值
|
|
|
|
|
|
assert_eq!(o.map_or_else(fn_default_for_result, fn_closure), 12);
|
|
|
assert_eq!(e.map_or_else(fn_default_for_result, fn_closure), 6);
|
|
|
}</code></pre></pre>
|
|
|
<h4 id="ok_or-and-ok_or_else"><a class="header" href="#ok_or-and-ok_or_else">ok_or() and ok_or_else()</a></h4>
|
|
|
<p>这两兄弟可以将 <code>Option</code> 类型转换为 <code>Result</code> 类型。其中 <code>ok_or</code> 接收一个默认的 <code>Err</code> 参数:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">fn main() {
|
|
|
const ERR_DEFAULT: &str = "error message";
|
|
|
|
|
|
let s = Some("abcde");
|
|
|
let n: Option<&str> = None;
|
|
|
|
|
|
let o: Result<&str, &str> = Ok("abcde");
|
|
|
let e: Result<&str, &str> = Err(ERR_DEFAULT);
|
|
|
|
|
|
assert_eq!(s.ok_or(ERR_DEFAULT), o); // Some(T) -> Ok(T)
|
|
|
assert_eq!(n.ok_or(ERR_DEFAULT), e); // None -> Err(default)
|
|
|
}</code></pre></pre>
|
|
|
<p>而 <code>ok_or_else</code> 接收一个闭包作为 <code>Err</code> 参数:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">fn main() {
|
|
|
let s = Some("abcde");
|
|
|
let n: Option<&str> = None;
|
|
|
let fn_err_message = || "error message";
|
|
|
|
|
|
let o: Result<&str, &str> = Ok("abcde");
|
|
|
let e: Result<&str, &str> = Err("error message");
|
|
|
|
|
|
assert_eq!(s.ok_or_else(fn_err_message), o); // Some(T) -> Ok(T)
|
|
|
assert_eq!(n.ok_or_else(fn_err_message), e); // None -> Err(default)
|
|
|
}</code></pre></pre>
|
|
|
<p>以上列出的只是常用的一部分，强烈建议大家看看标准库中有哪些可用的 API，在实际项目中，这些 API 将会非常有用: <a href="https://doc.rust-lang.org/stable/std/option/enum.Option.html">Option</a> 和 <a href="https://doc.rust-lang.org/stable/std/result/enum.Result.html">Result</a>。</p>
|
|
|
<h2 id="自定义错误类型"><a class="header" href="#自定义错误类型">自定义错误类型</a></h2>
|
|
|
<p>虽然标准库定义了大量的错误类型，但是一个严谨的项目，光使用这些错误类型往往是不够的，例如我们可能会为暴露给用户的错误定义相应的类型。</p>
|
|
|
<p>为了帮助我们更好的定义错误，Rust 在标准库中提供了一些可复用的特征，例如 <code>std::error::Error</code> 特征：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>use std::fmt::{Debug, Display};
|
|
|
|
|
|
pub trait Error: Debug + Display {
|
|
|
fn source(&self) -> Option<&(Error + 'static)> { ... }
|
|
|
}
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>当自定义类型实现该特征后，该类型就可以作为 <code>Err</code> 来使用，下面一起来看看。</p>
|
|
|
<blockquote>
|
|
|
<p>实际上，自定义错误类型只需要实现 <code>Debug</code> 和 <code>Display</code> 特征即可，<code>source</code> 方法是可选的，而 <code>Debug</code> 特征往往也无需手动实现，可以直接通过 <code>derive</code> 来派生</p>
|
|
|
</blockquote>
|
|
|
<h4 id="最简单的错误"><a class="header" href="#最简单的错误">最简单的错误</a></h4>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">use std::fmt;
|
|
|
|
|
|
// AppError 是自定义错误类型，它可以是当前包中定义的任何类型，在这里为了简化，我们使用了单元结构体作为例子。
|
|
|
// 为 AppError 自动派生 Debug 特征
|
|
|
#[derive(Debug)]
|
|
|
struct AppError;
|
|
|
|
|
|
// 为 AppError 实现 std::fmt::Display 特征
|
|
|
impl fmt::Display for AppError {
|
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
|
write!(f, "An Error Occurred, Please Try Again!") // user-facing output
|
|
|
}
|
|
|
}
|
|
|
|
|
|
// 一个示例函数用于产生 AppError 错误
|
|
|
fn produce_error() -> Result<(), AppError> {
|
|
|
Err(AppError)
|
|
|
}
|
|
|
|
|
|
fn main(){
|
|
|
match produce_error() {
|
|
|
Err(e) => eprintln!("{}", e),
|
|
|
_ => println!("No error"),
|
|
|
}
|
|
|
|
|
|
eprintln!("{:?}", produce_error()); // Err({ file: src/main.rs, line: 17 })
|
|
|
}</code></pre></pre>
|
|
|
<p>上面的例子很简单，我们定义了一个错误类型，当为它派生了 <code>Debug</code> 特征，同时手动实现了 <code>Display</code> 特征后，该错误类型就可以作为 <code>Err</code>来使用了。</p>
|
|
|
<p>事实上，实现 <code>Debug</code> 和 <code>Display</code> 特征并不是作为 <code>Err</code> 使用的必要条件，大家可以把这两个特征实现和相应使用去除，然后看看代码会否报错。既然如此，我们为何要为自定义类型实现这两个特征呢？原因有二:</p>
|
|
|
<ul>
|
|
|
<li>错误得打印输出后，才能有实际用处，而打印输出就需要实现这两个特征</li>
|
|
|
<li>可以将自定义错误转换成 <code>Box<dyn std::error:Error></code> 特征对象，在后面的<strong>归一化不同错误类型</strong>部分，我们会详细介绍</li>
|
|
|
</ul>
|
|
|
<h4 id="更详尽的错误"><a class="header" href="#更详尽的错误">更详尽的错误</a></h4>
|
|
|
<p>上一个例子中定义的错误非常简单，我们无法从错误中得到更多的信息，现在再来定义一个具有错误码和信息的错误:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">use std::fmt;
|
|
|
|
|
|
struct AppError {
|
|
|
code: usize,
|
|
|
message: String,
|
|
|
}
|
|
|
|
|
|
// 根据错误码显示不同的错误信息
|
|
|
impl fmt::Display for AppError {
|
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
|
let err_msg = match self.code {
|
|
|
404 => "Sorry, Can not find the Page!",
|
|
|
_ => "Sorry, something is wrong! Please Try Again!",
|
|
|
};
|
|
|
|
|
|
write!(f, "{}", err_msg)
|
|
|
}
|
|
|
}
|
|
|
|
|
|
impl fmt::Debug for AppError {
|
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
|
write!(
|
|
|
f,
|
|
|
"AppError {{ code: {}, message: {} }}",
|
|
|
self.code, self.message
|
|
|
)
|
|
|
}
|
|
|
}
|
|
|
|
|
|
fn produce_error() -> Result<(), AppError> {
|
|
|
Err(AppError {
|
|
|
code: 404,
|
|
|
message: String::from("Page not found"),
|
|
|
})
|
|
|
}
|
|
|
|
|
|
fn main() {
|
|
|
match produce_error() {
|
|
|
Err(e) => eprintln!("{}", e), // 抱歉，未找到指定的页面!
|
|
|
_ => println!("No error"),
|
|
|
}
|
|
|
|
|
|
eprintln!("{:?}", produce_error()); // Err(AppError { code: 404, message: Page not found })
|
|
|
|
|
|
eprintln!("{:#?}", produce_error());
|
|
|
// Err(
|
|
|
// AppError { code: 404, message: Page not found }
|
|
|
// )
|
|
|
}</code></pre></pre>
|
|
|
<p>在本例中，我们除了增加了错误码和消息外，还手动实现了 <code>Debug</code> 特征，原因在于，我们希望能自定义 <code>Debug</code> 的输出内容，而不是使用派生后系统提供的默认输出形式。</p>
|
|
|
<h4 id="错误转换-from-特征"><a class="header" href="#错误转换-from-特征">错误转换 <code>From</code> 特征</a></h4>
|
|
|
<p>标准库、三方库、本地库，各有各的精彩，各也有各的错误。那么问题就来了，我们该如何将其它的错误类型转换成自定义的错误类型？总不能神鬼牛魔，同台共舞吧。。</p>
|
|
|
<p>好在 Rust 为我们提供了 <code>std::convert::From</code> 特征:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>pub trait From<T>: Sized {
|
|
|
fn from(_: T) -> Self;
|
|
|
}
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<blockquote>
|
|
|
<p>事实上，该特征在之前的 <a href="https://course.rs/basic/result-error/result.html#%E4%BC%A0%E6%92%AD%E7%95%8C%E7%9A%84%E5%A4%A7%E6%98%8E%E6%98%9F-"><code>?</code> 操作符</a>章节中就有所介绍。</p>
|
|
|
<p>大家都使用过 <code>String::from</code> 函数吧？它可以通过 <code>&str</code> 来创建一个 <code>String</code>，其实该函数就是 <code>From</code> 特征提供的</p>
|
|
|
</blockquote>
|
|
|
<p>下面一起来看看如何为自定义类型实现 <code>From</code> 特征:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">use std::fs::File;
|
|
|
use std::io;
|
|
|
|
|
|
#[derive(Debug)]
|
|
|
struct AppError {
|
|
|
kind: String, // 错误类型
|
|
|
message: String, // 错误信息
|
|
|
}
|
|
|
|
|
|
// 为 AppError 实现 std::convert::From 特征，由于 From 包含在 std::prelude 中，因此可以直接简化引入。
|
|
|
// 实现 From<io::Error> 意味着我们可以将 io::Error 错误转换成自定义的 AppError 错误
|
|
|
impl From<io::Error> for AppError {
|
|
|
fn from(error: io::Error) -> Self {
|
|
|
AppError {
|
|
|
kind: String::from("io"),
|
|
|
message: error.to_string(),
|
|
|
}
|
|
|
}
|
|
|
}
|
|
|
|
|
|
fn main() -> Result<(), AppError> {
|
|
|
let _file = File::open("nonexistent_file.txt")?;
|
|
|
|
|
|
Ok(())
|
|
|
}
|
|
|
|
|
|
// --------------- 上述代码运行后输出 ---------------
|
|
|
Error: AppError { kind: "io", message: "No such file or directory (os error 2)" }</code></pre></pre>
|
|
|
<p>上面的代码中除了实现 <code>From</code> 外，还有一点特别重要，那就是 <code>?</code> 可以将错误进行隐式的强制转换：<code>File::open</code> 返回的是 <code>std::io::Error</code>， 我们并没有进行任何显式的转换，它就能自动变成 <code>AppError</code> ，这就是 <code>?</code> 的强大之处！</p>
|
|
|
<p>上面的例子只有一个标准库错误，再来看看多个不同的错误转换成 <code>AppError</code> 的实现：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">use std::fs::File;
|
|
|
use std::io::{self, Read};
|
|
|
use std::num;
|
|
|
|
|
|
#[derive(Debug)]
|
|
|
struct AppError {
|
|
|
kind: String,
|
|
|
message: String,
|
|
|
}
|
|
|
|
|
|
impl From<io::Error> for AppError {
|
|
|
fn from(error: io::Error) -> Self {
|
|
|
AppError {
|
|
|
kind: String::from("io"),
|
|
|
message: error.to_string(),
|
|
|
}
|
|
|
}
|
|
|
}
|
|
|
|
|
|
impl From<num::ParseIntError> for AppError {
|
|
|
fn from(error: num::ParseIntError) -> Self {
|
|
|
AppError {
|
|
|
kind: String::from("parse"),
|
|
|
message: error.to_string(),
|
|
|
}
|
|
|
}
|
|
|
}
|
|
|
|
|
|
fn main() -> Result<(), AppError> {
|
|
|
let mut file = File::open("hello_world.txt")?;
|
|
|
|
|
|
let mut content = String::new();
|
|
|
file.read_to_string(&mut content)?;
|
|
|
|
|
|
let _number: usize;
|
|
|
_number = content.parse()?;
|
|
|
|
|
|
Ok(())
|
|
|
}
|
|
|
|
|
|
|
|
|
// --------------- 上述代码运行后的可能输出 ---------------
|
|
|
|
|
|
// 01. 若 hello_world.txt 文件不存在
|
|
|
Error: AppError { kind: "io", message: "No such file or directory (os error 2)" }
|
|
|
|
|
|
// 02. 若用户没有相关的权限访问 hello_world.txt
|
|
|
Error: AppError { kind: "io", message: "Permission denied (os error 13)" }
|
|
|
|
|
|
// 03. 若 hello_world.txt 包含有非数字的内容，例如 Hello, world!
|
|
|
Error: AppError { kind: "parse", message: "invalid digit found in string" }</code></pre></pre>
|
|
|
<h2 id="归一化不同的错误类型"><a class="header" href="#归一化不同的错误类型">归一化不同的错误类型</a></h2>
|
|
|
<p>至此，关于 Rust 的错误处理大家已经了若指掌了，下面再来看看一些实战中的问题。</p>
|
|
|
<p>在实际项目中，我们往往会为不同的错误定义不同的类型，这样做非常好，但是如果你要在一个函数中返回不同的错误呢？例如：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">use std::fs::read_to_string;
|
|
|
|
|
|
fn main() -> Result<(), std::io::Error> {
|
|
|
let html = render()?;
|
|
|
println!("{}", html);
|
|
|
Ok(())
|
|
|
}
|
|
|
|
|
|
fn render() -> Result<String, std::io::Error> {
|
|
|
let file = std::env::var("MARKDOWN")?;
|
|
|
let source = read_to_string(file)?;
|
|
|
Ok(source)
|
|
|
}</code></pre></pre>
|
|
|
<p>上面的代码会报错，原因在于 <code>render</code> 函数中的两个 <code>?</code> 返回的实际上是不同的错误：<code>env::var()</code> 返回的是 <code>std::env::VarError</code>，而 <code>read_to_string</code> 返回的是 <code>std::io::Error</code>。</p>
|
|
|
<p>为了满足 <code>render</code> 函数的签名，我们就需要将 <code>env::VarError</code> 和 <code>io::Error</code> 归一化为同一种错误类型。要实现这个目的有三种方式:</p>
|
|
|
<ul>
|
|
|
<li>使用特征对象 <code>Box<dyn Error></code></li>
|
|
|
<li>自定义错误类型</li>
|
|
|
<li>使用 <code>thiserror</code></li>
|
|
|
</ul>
|
|
|
<p>下面依次来看看相关的解决方式。</p>
|
|
|
<h4 id="boxdyn-error"><a class="header" href="#boxdyn-error"><code>Box<dyn Error></code></a></h4>
|
|
|
<p>大家还记得我们之前提到的 <code>std::error::Error</code> 特征吧，当时有说：自定义类型实现 <code>Debug + Display</code> 特征的主要原因就是为了能转换成 <code>Error</code> 的特征对象，而特征对象恰恰是在同一个地方使用不同类型的关键:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">use std::fs::read_to_string;
|
|
|
use std::error::Error;
|
|
|
fn main() -> Result<(), Box<dyn Error>> {
|
|
|
let html = render()?;
|
|
|
println!("{}", html);
|
|
|
Ok(())
|
|
|
}
|
|
|
|
|
|
fn render() -> Result<String, Box<dyn Error>> {
|
|
|
let file = std::env::var("MARKDOWN")?;
|
|
|
let source = read_to_string(file)?;
|
|
|
Ok(source)
|
|
|
}</code></pre></pre>
|
|
|
<p>这个方法很简单，在绝大多数场景中，性能也非常够用，但是有一个问题：<code>Result</code> 实际上不会限制错误的类型，也就是一个类型就算不实现 <code>Error</code> 特征，它依然可以在 <code>Result<T, E></code> 中作为 <code>E</code> 来使用，此时这种特征对象的解决方案就无能为力了。</p>
|
|
|
<h4 id="自定义错误类型-1"><a class="header" href="#自定义错误类型-1">自定义错误类型</a></h4>
|
|
|
<p>与特征对象相比，自定义错误类型麻烦归麻烦，但是它非常灵活，因此也不具有上面的类似限制:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">use std::fs::read_to_string;
|
|
|
|
|
|
fn main() -> Result<(), MyError> {
|
|
|
let html = render()?;
|
|
|
println!("{}", html);
|
|
|
Ok(())
|
|
|
}
|
|
|
|
|
|
fn render() -> Result<String, MyError> {
|
|
|
let file = std::env::var("MARKDOWN")?;
|
|
|
let source = read_to_string(file)?;
|
|
|
Ok(source)
|
|
|
}
|
|
|
|
|
|
#[derive(Debug)]
|
|
|
enum MyError {
|
|
|
EnvironmentVariableNotFound,
|
|
|
IOError(std::io::Error),
|
|
|
}
|
|
|
|
|
|
impl From<std::env::VarError> for MyError {
|
|
|
fn from(_: std::env::VarError) -> Self {
|
|
|
Self::EnvironmentVariableNotFound
|
|
|
}
|
|
|
}
|
|
|
|
|
|
impl From<std::io::Error> for MyError {
|
|
|
fn from(value: std::io::Error) -> Self {
|
|
|
Self::IOError(value)
|
|
|
}
|
|
|
}
|
|
|
|
|
|
impl std::error::Error for MyError {}
|
|
|
|
|
|
impl std::fmt::Display for MyError {
|
|
|
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
|
|
|
match self {
|
|
|
MyError::EnvironmentVariableNotFound => write!(f, "Environment variable not found"),
|
|
|
MyError::IOError(err) => write!(f, "IO Error: {}", err.to_string()),
|
|
|
}
|
|
|
}
|
|
|
}</code></pre></pre>
|
|
|
<p>上面代码中有一行值得注意：<code>impl std::error::Error for MyError {}</code> ，只有为自定义错误类型实现 <code>Error</code> 特征后，才能转换成相应的特征对象。</p>
|
|
|
<p>不得不说，真是啰嗦啊。因此在能用特征对象的时候，建议大家还是使用特征对象，无论如何，代码可读性还是很重要的！</p>
|
|
|
<p>上面的第二种方式灵活归灵活，啰嗦也是真啰嗦，好在 Rust 的社区为我们提供了 <code>thiserror</code> 解决方案，下面一起来看看该如何简化 Rust 中的错误处理。</p>
|
|
|
<h2 id="简化错误处理"><a class="header" href="#简化错误处理">简化错误处理</a></h2>
|
|
|
<p>对于开发者而言，错误处理是代码中打交道最多的部分之一，因此选择一把趁手的武器也很重要，它可以帮助我们节省大量的时间和精力，好钢应该用在代码逻辑而不是冗长的错误处理上。</p>
|
|
|
<h4 id="thiserror"><a class="header" href="#thiserror">thiserror</a></h4>
|
|
|
<p><a href="https://github.com/dtolnay/thiserror"><code>thiserror</code></a>可以帮助我们简化上面的第二种解决方案：</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">use std::fs::read_to_string;
|
|
|
|
|
|
fn main() -> Result<(), MyError> {
|
|
|
let html = render()?;
|
|
|
println!("{}", html);
|
|
|
Ok(())
|
|
|
}
|
|
|
|
|
|
fn render() -> Result<String, MyError> {
|
|
|
let file = std::env::var("MARKDOWN")?;
|
|
|
let source = read_to_string(file)?;
|
|
|
Ok(source)
|
|
|
}
|
|
|
|
|
|
#[derive(thiserror::Error, Debug)]
|
|
|
enum MyError {
|
|
|
#[error("Environment variable not found")]
|
|
|
EnvironmentVariableNotFound(#[from] std::env::VarError),
|
|
|
#[error(transparent)]
|
|
|
IOError(#[from] std::io::Error),
|
|
|
}</code></pre></pre>
|
|
|
<p>如上所示，只要简单写写注释，就可以实现错误处理了，惊不惊喜？</p>
|
|
|
<h4 id="error-chain"><a class="header" href="#error-chain">error-chain</a></h4>
|
|
|
<p><a href="https://github.com/rust-lang-deprecated/error-chain"><code>error-chain</code></a> 也是简单好用的库，可惜不再维护了，但是我觉得它依然可以在合适的地方大放光彩，值得大家去了解下。</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">use std::fs::read_to_string;
|
|
|
|
|
|
error_chain::error_chain! {
|
|
|
foreign_links {
|
|
|
EnvironmentVariableNotFound(::std::env::VarError);
|
|
|
IOError(::std::io::Error);
|
|
|
}
|
|
|
}
|
|
|
|
|
|
fn main() -> Result<()> {
|
|
|
let html = render()?;
|
|
|
println!("{}", html);
|
|
|
Ok(())
|
|
|
}
|
|
|
|
|
|
fn render() -> Result<String> {
|
|
|
let file = std::env::var("MARKDOWN")?;
|
|
|
let source = read_to_string(file)?;
|
|
|
Ok(source)
|
|
|
}</code></pre></pre>
|
|
|
<p>喏，简单吧？使用 <code>error-chain</code> 的宏你可以获得：<code>Error</code> 结构体，错误类型 <code>ErrorKind</code> 枚举 以及一个自定义的 <code>Result</code> 类型。</p>
|
|
|
<h4 id="anyhow"><a class="header" href="#anyhow">anyhow</a></h4>
|
|
|
<p><a href="https://github.com/dtolnay/anyhow"><code>anyhow</code></a> 和 <code>thiserror</code> 是同一个作者开发的，这里是作者关于 <code>anyhow</code> 和 <code>thiserror</code> 的原话：</p>
|
|
|
<blockquote>
|
|
|
<p>如果你想要设计自己的错误类型，同时给调用者提供具体的信息时，就使用 <code>thiserror</code>，例如当你在开发一个三方库代码时。如果你只想要简单，就使用 <code>anyhow</code>，例如在自己的应用服务中。</p>
|
|
|
</blockquote>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">use std::fs::read_to_string;
|
|
|
|
|
|
use anyhow::Result;
|
|
|
|
|
|
fn main() -> Result<()> {
|
|
|
let html = render()?;
|
|
|
println!("{}", html);
|
|
|
Ok(())
|
|
|
}
|
|
|
|
|
|
fn render() -> Result<String> {
|
|
|
let file = std::env::var("MARKDOWN")?;
|
|
|
let source = read_to_string(file)?;
|
|
|
Ok(source)
|
|
|
}</code></pre></pre>
|
|
|
<p>关于如何选用 <code>thiserror</code> 和 <code>anyhow</code> 只需要遵循一个原则即可：<strong>是否关注自定义错误消息</strong>，关注则使用 <code>thiserror</code>（常见业务代码），否则使用 <code>anyhow</code>（编写第三方库代码）。</p>
|
|
|
<h2 id="总结"><a class="header" href="#总结">总结</a></h2>
|
|
|
<p>Rust 一个为人津津乐道的点就是强大、易用的错误处理，对于新手来说，这个机制可能会有些复杂，但是一旦体会到了其中的好处，你将跟我一样沉醉其中不能自拔。</p>
|
|
|
|
|
|
<div id="giscus-container"></div>
|
|
|
</main>
|
|
|
|
|
|
<nav class="nav-wrapper" aria-label="Page navigation">
|
|
|
<!-- Mobile navigation buttons -->
|
|
|
<a rel="prev" href="../advance/global-variable.html" class="mobile-nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
|
|
|
<i class="fa fa-angle-left"></i>
|
|
|
</a>
|
|
|
|
|
|
<a rel="next prefetch" href="../advance/unsafe/intro.html" class="mobile-nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
|
|
|
<i class="fa fa-angle-right"></i>
|
|
|
</a>
|
|
|
|
|
|
<div style="clear: both"></div>
|
|
|
</nav>
|
|
|
</div>
|
|
|
</div>
|
|
|
|
|
|
<nav class="nav-wide-wrapper" aria-label="Page navigation">
|
|
|
<a rel="prev" href="../advance/global-variable.html" class="nav-chapters previous" title="Previous chapter" aria-label="Previous chapter" aria-keyshortcuts="Left">
|
|
|
<i class="fa fa-angle-left"></i>
|
|
|
</a>
|
|
|
|
|
|
<a rel="next prefetch" href="../advance/unsafe/intro.html" class="nav-chapters next" title="Next chapter" aria-label="Next chapter" aria-keyshortcuts="Right">
|
|
|
<i class="fa fa-angle-right"></i>
|
|
|
</a>
|
|
|
</nav>
|
|
|
|
|
|
</div>
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
<script>
|
|
|
window.playground_copyable = true;
|
|
|
</script>
|
|
|
|
|
|
<script src="../ace.js"></script>
|
|
|
<script src="../editor.js"></script>
|
|
|
<script src="../mode-rust.js"></script>
|
|
|
<script src="../theme-dawn.js"></script>
|
|
|
<script src="../theme-tomorrow_night.js"></script>
|
|
|
|
|
|
<script src="../elasticlunr.min.js"></script>
|
|
|
<script src="../mark.min.js"></script>
|
|
|
<script src="../searcher.js"></script>
|
|
|
|
|
|
<script src="../clipboard.min.js"></script>
|
|
|
<script src="../highlight.js"></script>
|
|
|
<script src="../book.js"></script>
|
|
|
|
|
|
<script type="text/javascript" charset="utf-8">
|
|
|
var pagePath = "advance/errors.md"
|
|
|
</script>
|
|
|
|
|
|
|
|
|
<!-- Custom JS scripts -->
|
|
|
<script src="../assets/custom.js"></script>
|
|
|
<script src="../assets/bigPicture.js"></script>
|
|
|
|
|
|
|
|
|
</div>
|
|
|
</body>
|
|
|
</html> |
