|
|
<!DOCTYPE HTML>
|
|
|
<html lang="zh-CN" class="light" dir="ltr">
|
|
|
<head>
|
|
|
<!-- Book generated using mdBook -->
|
|
|
<meta charset="UTF-8">
|
|
|
<title>使用 use 引入模块及受限可见性 - 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 expanded "><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 expanded "><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 expanded "><a href="../../basic/crate-module/use.html" class="active"><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 "><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 "><a href="../../advance/errors.html"><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/basic/crate-module/use.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="使用-use-及受限可见性"><a class="header" href="#使用-use-及受限可见性">使用 use 及受限可见性</a></h1>
|
|
|
<p>如果代码中,通篇都是 <code>crate::front_of_house::hosting::add_to_waitlist</code> 这样的函数调用形式,我不知道有谁会喜欢,也许靠代码行数赚工资的人会很喜欢,但是强迫症肯定受不了,悲伤的是程序员大多都有强迫症。。。</p>
|
|
|
<p>因此我们需要一个办法来简化这种使用方式,在 Rust 中,可以使用 <code>use</code> 关键字把路径提前引入到当前作用域中,随后的调用就可以省略该路径,极大地简化了代码。</p>
|
|
|
<h2 id="基本引入方式"><a class="header" href="#基本引入方式">基本引入方式</a></h2>
|
|
|
<p>在 Rust 中,引入模块中的项有两种方式:<a href="https://course.rs/basic/crate-module/module.html#%E7%94%A8%E8%B7%AF%E5%BE%84%E5%BC%95%E7%94%A8%E6%A8%A1%E5%9D%97">绝对路径和相对路径</a>,这两者在前面章节都有讲过,就不再赘述,先来看看使用绝对路径的引入方式。</p>
|
|
|
<h4 id="绝对路径引入模块"><a class="header" href="#绝对路径引入模块">绝对路径引入模块</a></h4>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>mod front_of_house {
|
|
|
pub mod hosting {
|
|
|
pub fn add_to_waitlist() {}
|
|
|
}
|
|
|
}
|
|
|
|
|
|
use crate::front_of_house::hosting;
|
|
|
|
|
|
pub fn eat_at_restaurant() {
|
|
|
hosting::add_to_waitlist();
|
|
|
hosting::add_to_waitlist();
|
|
|
hosting::add_to_waitlist();
|
|
|
}
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>这里,我们使用 <code>use</code> 和绝对路径的方式,将 <code>hosting</code> 模块引入到当前作用域中,然后只需通过 <code>hosting::add_to_waitlist</code> 的方式,即可调用目标模块中的函数,相比 <code>crate::front_of_house::hosting::add_to_waitlist()</code> 的方式要简单的多,那么还能更简单吗?</p>
|
|
|
<h4 id="相对路径引入模块中的函数"><a class="header" href="#相对路径引入模块中的函数">相对路径引入模块中的函数</a></h4>
|
|
|
<p>在下面代码中,我们不仅要使用相对路径进行引入,而且与上面引入 <code>hosting</code> 模块不同,直接引入该模块中的 <code>add_to_waitlist</code> 函数:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>mod front_of_house {
|
|
|
pub mod hosting {
|
|
|
pub fn add_to_waitlist() {}
|
|
|
}
|
|
|
}
|
|
|
|
|
|
use front_of_house::hosting::add_to_waitlist;
|
|
|
|
|
|
pub fn eat_at_restaurant() {
|
|
|
add_to_waitlist();
|
|
|
add_to_waitlist();
|
|
|
add_to_waitlist();
|
|
|
}
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>很明显,三兄弟又变得更短了,不过,怎么觉得这句话怪怪的。。</p>
|
|
|
<h4 id="引入模块还是函数"><a class="header" href="#引入模块还是函数">引入模块还是函数</a></h4>
|
|
|
<p>从使用简洁性来说,引入函数自然是更甚一筹,但是在某些时候,引入模块会更好:</p>
|
|
|
<ul>
|
|
|
<li>需要引入同一个模块的多个函数</li>
|
|
|
<li>作用域中存在同名函数</li>
|
|
|
</ul>
|
|
|
<p>在以上两种情况中,使用 <code>use front_of_house::hosting;</code> 引入模块要比 <code>use front_of_house::hosting::add_to_waitlist;</code> 引入函数更好。</p>
|
|
|
<p>例如,如果想使用 <code>HashMap</code>,那么直接引入该结构体是比引入模块更好的选择,因为在 <code>collections</code> 模块中,我们只需要使用一个 <code>HashMap</code> 结构体:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">use std::collections::HashMap;
|
|
|
|
|
|
fn main() {
|
|
|
let mut map = HashMap::new();
|
|
|
map.insert(1, 2);
|
|
|
}</code></pre></pre>
|
|
|
<p>其实严格来说,对于引用方式并没有需要遵守的惯例,主要还是取决于你的喜好,不过我们建议:<strong>优先使用最细粒度(引入函数、结构体等)的引用方式,如果引起了某种麻烦(例如前面两种情况),再使用引入模块的方式</strong>。</p>
|
|
|
<h2 id="避免同名引用"><a class="header" href="#避免同名引用">避免同名引用</a></h2>
|
|
|
<p>根据上一章节的内容,我们只要保证同一个模块中不存在同名项就行,模块之间、包之间的同名,谁管得着谁啊,话虽如此,一起看看,如果遇到同名的情况该如何处理。</p>
|
|
|
<h4 id="模块函数"><a class="header" href="#模块函数">模块::函数</a></h4>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>use std::fmt;
|
|
|
use std::io;
|
|
|
|
|
|
fn function1() -> fmt::Result {
|
|
|
// --snip--
|
|
|
}
|
|
|
|
|
|
fn function2() -> io::Result<()> {
|
|
|
// --snip--
|
|
|
}
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>上面的例子给出了很好的解决方案,使用模块引入的方式,具体的 <code>Result</code> 通过 <code>模块::Result</code> 的方式进行调用。</p>
|
|
|
<p>可以看出,避免同名冲突的关键,就是使用<strong>父模块的方式来调用</strong>,除此之外,还可以给予引入的项起一个别名。</p>
|
|
|
<h4 id="as-别名引用"><a class="header" href="#as-别名引用"><code>as</code> 别名引用</a></h4>
|
|
|
<p>对于同名冲突问题,还可以使用 <code>as</code> 关键字来解决,它可以赋予引入项一个全新的名称:</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::Result;
|
|
|
use std::io::Result as IoResult;
|
|
|
|
|
|
fn function1() -> Result {
|
|
|
// --snip--
|
|
|
}
|
|
|
|
|
|
fn function2() -> IoResult<()> {
|
|
|
// --snip--
|
|
|
}
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>如上所示,首先通过 <code>use std::io::Result</code> 将 <code>Result</code> 引入到作用域,然后使用 <code>as</code> 给予它一个全新的名称 <code>IoResult</code>,这样就不会再产生冲突:</p>
|
|
|
<ul>
|
|
|
<li><code>Result</code> 代表 <code>std::fmt::Result</code></li>
|
|
|
<li><code>IoResult</code> 代表 <code>std:io::Result</code></li>
|
|
|
</ul>
|
|
|
<h2 id="引入项再导出"><a class="header" href="#引入项再导出">引入项再导出</a></h2>
|
|
|
<p>当外部的模块项 <code>A</code> 被引入到当前模块中时,它的可见性自动被设置为私有的,如果你希望允许其它外部代码引用我们的模块项 <code>A</code>,那么可以对它进行再导出:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>mod front_of_house {
|
|
|
pub mod hosting {
|
|
|
pub fn add_to_waitlist() {}
|
|
|
}
|
|
|
}
|
|
|
|
|
|
pub use crate::front_of_house::hosting;
|
|
|
|
|
|
pub fn eat_at_restaurant() {
|
|
|
hosting::add_to_waitlist();
|
|
|
hosting::add_to_waitlist();
|
|
|
hosting::add_to_waitlist();
|
|
|
}
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>如上,使用 <code>pub use</code> 即可实现。这里 <code>use</code> 代表引入 <code>hosting</code> 模块到当前作用域,<code>pub</code> 表示将该引入的内容再度设置为可见。</p>
|
|
|
<p>当你希望将内部的实现细节隐藏起来或者按照某个目的组织代码时,可以使用 <code>pub use</code> 再导出,例如统一使用一个模块来提供对外的 API,那该模块就可以引入其它模块中的 API,然后进行再导出,最终对于用户来说,所有的 API 都是由一个模块统一提供的。</p>
|
|
|
<h2 id="使用第三方包"><a class="header" href="#使用第三方包">使用第三方包</a></h2>
|
|
|
<p>之前我们一直在引入标准库模块或者自定义模块,现在来引入下第三方包中的模块,关于如何引入外部依赖,我们在 <a href="https://course.rs/first-try/cargo.html#package-%E9%85%8D%E7%BD%AE%E6%AE%B5%E8%90%BD">Cargo 入门</a>中就有讲,这里直接给出操作步骤:</p>
|
|
|
<ol>
|
|
|
<li>修改 <code>Cargo.toml</code> 文件,在 <code>[dependencies]</code> 区域添加一行:<code>rand = "0.8.3"</code></li>
|
|
|
<li>此时,如果你用的是 <code>VSCode</code> 和 <code>rust-analyzer</code> 插件,该插件会自动拉取该库,你可能需要等它完成后,再进行下一步(VSCode 左下角有提示)</li>
|
|
|
</ol>
|
|
|
<p>好了,此时,<code>rand</code> 包已经被我们添加到依赖中,下一步就是在代码中使用:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">use rand::Rng;
|
|
|
|
|
|
fn main() {
|
|
|
let secret_number = rand::thread_rng().gen_range(1..101);
|
|
|
}</code></pre></pre>
|
|
|
<p>这里使用 <code>use</code> 引入了第三方包 <code>rand</code> 中的 <code>Rng</code> 特征,因为我们需要调用的 <code>gen_range</code> 方法定义在该特征中。</p>
|
|
|
<h4 id="cratesiolibrs"><a class="header" href="#cratesiolibrs">crates.io,lib.rs</a></h4>
|
|
|
<p>Rust 社区已经为我们贡献了大量高质量的第三方包,你可以在 <code>crates.io</code> 或者 <code>lib.rs</code> 中检索和使用,从目前来说查找包更推荐 <code>lib.rs</code>,搜索功能更强大,内容展示也更加合理,但是下载依赖包还是得用<code>crates.io</code>。</p>
|
|
|
<p>你可以在网站上搜索 <code>rand</code> 包,看看它的文档使用方式是否和我们之前引入方式相一致:在网上找到想要的包,然后将你想要的包和版本信息写入到 <code>Cargo.toml</code> 中。</p>
|
|
|
<h2 id="使用--简化引入方式"><a class="header" href="#使用--简化引入方式">使用 <code>{}</code> 简化引入方式</a></h2>
|
|
|
<p>对于以下一行一行的引入方式:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>use std::collections::HashMap;
|
|
|
use std::collections::BTreeMap;
|
|
|
use std::collections::HashSet;
|
|
|
|
|
|
use std::cmp::Ordering;
|
|
|
use std::io;
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>可以使用 <code>{}</code> 来一起引入进来,在大型项目中,使用这种方式来引入,可以减少大量 <code>use</code> 的使用:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>use std::collections::{HashMap,BTreeMap,HashSet};
|
|
|
use std::{cmp::Ordering, io};
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>对于下面的同时引入模块和模块中的项:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>use std::io;
|
|
|
use std::io::Write;
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>可以使用 <code>{}</code> 的方式进行简化:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>use std::io::{self, Write};
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<h4 id="self"><a class="header" href="#self">self</a></h4>
|
|
|
<p>上面使用到了模块章节提到的 <code>self</code> 关键字,用来替代模块自身,结合上一节中的 <code>self</code>,可以得出它在模块中的两个用途:</p>
|
|
|
<ul>
|
|
|
<li><code>use self::xxx</code>,表示加载当前模块中的 <code>xxx</code>。此时 <code>self</code> 可省略</li>
|
|
|
<li><code>use xxx::{self, yyy}</code>,表示,加载当前路径下模块 <code>xxx</code> 本身,以及模块 <code>xxx</code> 下的 <code>yyy</code></li>
|
|
|
</ul>
|
|
|
<h2 id="使用--引入模块下的所有项"><a class="header" href="#使用--引入模块下的所有项">使用 <code>*</code> 引入模块下的所有项</a></h2>
|
|
|
<p>对于之前一行一行引入 <code>std::collections</code> 的方式,我们还可以使用</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>use std::collections::*;
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>以上这种方式来引入 <code>std::collections</code> 模块下的所有公共项,这些公共项自然包含了 <code>HashMap</code>,<code>HashSet</code> 等想手动引入的集合类型。</p>
|
|
|
<p>当使用 <code>*</code> 来引入的时候要格外小心,因为你很难知道到底哪些被引入到了当前作用域中,有哪些会和你自己程序中的名称相冲突:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">use std::collections::*;
|
|
|
|
|
|
struct HashMap;
|
|
|
fn main() {
|
|
|
let mut v = HashMap::new();
|
|
|
v.insert("a", 1);
|
|
|
}</code></pre></pre>
|
|
|
<p>以上代码中,<code>std::collections::HashMap</code> 被 <code>*</code> 引入到当前作用域,但是由于存在另一个同名的结构体,因此 <code>HashMap::new</code> 根本不存在,因为对于编译器来说,本地同名类型的优先级更高。</p>
|
|
|
<p>在实际项目中,这种引用方式往往用于快速写测试代码,它可以把所有东西一次性引入到 <code>tests</code> 模块中。</p>
|
|
|
<h2 id="受限的可见性"><a class="header" href="#受限的可见性">受限的可见性</a></h2>
|
|
|
<p>在上一节中,我们学习了<a href="https://course.rs/basic/crate-module/module.html#%E4%BB%A3%E7%A0%81%E5%8F%AF%E8%A7%81%E6%80%A7">可见性</a>这个概念,这也是模块体系中最为核心的概念,控制了模块中哪些内容可以被外部看见,但是在实际使用时,光被外面看到还不行,我们还想控制哪些人能看,这就是 Rust 提供的受限可见性。</p>
|
|
|
<p>例如,在 Rust 中,包是一个模块树,我们可以通过 <code>pub(crate) item;</code> 这种方式来实现:<code>item</code> 虽然是对外可见的,但是只在当前包内可见,外部包无法引用到该 <code>item</code>。</p>
|
|
|
<p>所以,如果我们想要让某一项可以在整个包中都可以被使用,那么有两种办法:</p>
|
|
|
<ul>
|
|
|
<li>在包根中定义一个非 <code>pub</code> 类型的 <code>X</code>(父模块的项对子模块都是可见的,因此包根中的项对模块树上的所有模块都可见)</li>
|
|
|
<li>在子模块中定义一个 <code>pub</code> 类型的 <code>Y</code>,同时通过 <code>use</code> 将其引入到包根</li>
|
|
|
</ul>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>mod a {
|
|
|
pub mod b {
|
|
|
pub fn c() {
|
|
|
println!("{:?}",crate::X);
|
|
|
}
|
|
|
|
|
|
#[derive(Debug)]
|
|
|
pub struct Y;
|
|
|
}
|
|
|
}
|
|
|
|
|
|
#[derive(Debug)]
|
|
|
struct X;
|
|
|
use a::b::Y;
|
|
|
fn d() {
|
|
|
println!("{:?}",Y);
|
|
|
}
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>以上代码充分说明了之前两种办法的使用方式,但是有时我们会遇到这两种方法都不太好用的时候。例如希望对于某些特定的模块可见,但是对于其他模块又不可见:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>// 目标:`a` 导出 `I`、`bar` and `foo`,其他的不导出
|
|
|
pub mod a {
|
|
|
pub const I: i32 = 3;
|
|
|
|
|
|
fn semisecret(x: i32) -> i32 {
|
|
|
use self::b::c::J;
|
|
|
x + J
|
|
|
}
|
|
|
|
|
|
pub fn bar(z: i32) -> i32 {
|
|
|
semisecret(I) * z
|
|
|
}
|
|
|
pub fn foo(y: i32) -> i32 {
|
|
|
semisecret(I) + y
|
|
|
}
|
|
|
|
|
|
mod b {
|
|
|
mod c {
|
|
|
const J: i32 = 4;
|
|
|
}
|
|
|
}
|
|
|
}
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>这段代码会报错,因为与父模块中的项对子模块可见相反,子模块中的项对父模块是不可见的。这里 <code>semisecret</code> 方法中,<code>a</code> -> <code>b</code> -> <code>c</code> 形成了父子模块链,那 <code>c</code> 中的 <code>J</code> 自然对 <code>a</code> 模块不可见。</p>
|
|
|
<p>如果使用之前的可见性方式,那么想保持 <code>J</code> 私有,同时让 <code>a</code> 继续使用 <code>semisecret</code> 函数的办法是将该函数移动到 <code>c</code> 模块中,然后用 <code>pub use</code> 将 <code>semisecret</code> 函数进行再导出:</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>pub mod a {
|
|
|
pub const I: i32 = 3;
|
|
|
|
|
|
use self::b::semisecret;
|
|
|
|
|
|
pub fn bar(z: i32) -> i32 {
|
|
|
semisecret(I) * z
|
|
|
}
|
|
|
pub fn foo(y: i32) -> i32 {
|
|
|
semisecret(I) + y
|
|
|
}
|
|
|
|
|
|
mod b {
|
|
|
pub use self::c::semisecret;
|
|
|
mod c {
|
|
|
const J: i32 = 4;
|
|
|
pub fn semisecret(x: i32) -> i32 {
|
|
|
x + J
|
|
|
}
|
|
|
}
|
|
|
}
|
|
|
}
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>这段代码说实话问题不大,但是有些破坏了我们之前的逻辑,如果想保持代码逻辑,同时又只让 <code>J</code> 在 <code>a</code> 内可见该怎么办?</p>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021"><span class="boring">#![allow(unused)]
|
|
|
</span><span class="boring">fn main() {
|
|
|
</span>pub mod a {
|
|
|
pub const I: i32 = 3;
|
|
|
|
|
|
fn semisecret(x: i32) -> i32 {
|
|
|
use self::b::c::J;
|
|
|
x + J
|
|
|
}
|
|
|
|
|
|
pub fn bar(z: i32) -> i32 {
|
|
|
semisecret(I) * z
|
|
|
}
|
|
|
pub fn foo(y: i32) -> i32 {
|
|
|
semisecret(I) + y
|
|
|
}
|
|
|
|
|
|
mod b {
|
|
|
pub(in crate::a) mod c {
|
|
|
pub(in crate::a) const J: i32 = 4;
|
|
|
}
|
|
|
}
|
|
|
}
|
|
|
<span class="boring">}</span></code></pre></pre>
|
|
|
<p>通过 <code>pub(in crate::a)</code> 的方式,我们指定了模块 <code>c</code> 和常量 <code>J</code> 的可见范围都只是 <code>a</code> 模块中,<code>a</code> 之外的模块是完全访问不到它们的。</p>
|
|
|
<h4 id="限制可见性语法"><a class="header" href="#限制可见性语法">限制可见性语法</a></h4>
|
|
|
<p><code>pub(crate)</code> 或 <code>pub(in crate::a)</code> 就是限制可见性语法,前者是限制在整个包内可见,后者是通过绝对路径,限制在包内的某个模块内可见,总结一下:</p>
|
|
|
<ul>
|
|
|
<li><code>pub</code> 意味着可见性无任何限制</li>
|
|
|
<li><code>pub(crate)</code> 表示在当前包可见</li>
|
|
|
<li><code>pub(self)</code> 在当前模块可见</li>
|
|
|
<li><code>pub(super)</code> 在父模块可见</li>
|
|
|
<li><code>pub(in <path>)</code> 表示在某个路径代表的模块中可见,其中 <code>path</code> 必须是父模块或者祖先模块</li>
|
|
|
</ul>
|
|
|
<h4 id="一个综合例子"><a class="header" href="#一个综合例子">一个综合例子</a></h4>
|
|
|
<pre><pre class="playground"><code class="language-rust edition2021">// 一个名为 `my_mod` 的模块
|
|
|
mod my_mod {
|
|
|
// 模块中的项默认具有私有的可见性
|
|
|
fn private_function() {
|
|
|
println!("called `my_mod::private_function()`");
|
|
|
}
|
|
|
|
|
|
// 使用 `pub` 修饰语来改变默认可见性。
|
|
|
pub fn function() {
|
|
|
println!("called `my_mod::function()`");
|
|
|
}
|
|
|
|
|
|
// 在同一模块中,项可以访问其它项,即使它是私有的。
|
|
|
pub fn indirect_access() {
|
|
|
print!("called `my_mod::indirect_access()`, that\n> ");
|
|
|
private_function();
|
|
|
}
|
|
|
|
|
|
// 模块也可以嵌套
|
|
|
pub mod nested {
|
|
|
pub fn function() {
|
|
|
println!("called `my_mod::nested::function()`");
|
|
|
}
|
|
|
|
|
|
#[allow(dead_code)]
|
|
|
fn private_function() {
|
|
|
println!("called `my_mod::nested::private_function()`");
|
|
|
}
|
|
|
|
|
|
// 使用 `pub(in path)` 语法定义的函数只在给定的路径中可见。
|
|
|
// `path` 必须是父模块(parent module)或祖先模块(ancestor module)
|
|
|
pub(in crate::my_mod) fn public_function_in_my_mod() {
|
|
|
print!("called `my_mod::nested::public_function_in_my_mod()`, that\n > ");
|
|
|
public_function_in_nested()
|
|
|
}
|
|
|
|
|
|
// 使用 `pub(self)` 语法定义的函数则只在当前模块中可见。
|
|
|
pub(self) fn public_function_in_nested() {
|
|
|
println!("called `my_mod::nested::public_function_in_nested");
|
|
|
}
|
|
|
|
|
|
// 使用 `pub(super)` 语法定义的函数只在父模块中可见。
|
|
|
pub(super) fn public_function_in_super_mod() {
|
|
|
println!("called my_mod::nested::public_function_in_super_mod");
|
|
|
}
|
|
|
}
|
|
|
|
|
|
pub fn call_public_function_in_my_mod() {
|
|
|
print!("called `my_mod::call_public_funcion_in_my_mod()`, that\n> ");
|
|
|
nested::public_function_in_my_mod();
|
|
|
print!("> ");
|
|
|
nested::public_function_in_super_mod();
|
|
|
}
|
|
|
|
|
|
// `pub(crate)` 使得函数只在当前包中可见
|
|
|
pub(crate) fn public_function_in_crate() {
|
|
|
println!("called `my_mod::public_function_in_crate()");
|
|
|
}
|
|
|
|
|
|
// 嵌套模块的可见性遵循相同的规则
|
|
|
mod private_nested {
|
|
|
#[allow(dead_code)]
|
|
|
pub fn function() {
|
|
|
println!("called `my_mod::private_nested::function()`");
|
|
|
}
|
|
|
}
|
|
|
}
|
|
|
|
|
|
fn function() {
|
|
|
println!("called `function()`");
|
|
|
}
|
|
|
|
|
|
fn main() {
|
|
|
// 模块机制消除了相同名字的项之间的歧义。
|
|
|
function();
|
|
|
my_mod::function();
|
|
|
|
|
|
// 公有项,包括嵌套模块内的,都可以在父模块外部访问。
|
|
|
my_mod::indirect_access();
|
|
|
my_mod::nested::function();
|
|
|
my_mod::call_public_function_in_my_mod();
|
|
|
|
|
|
// pub(crate) 项可以在同一个 crate 中的任何地方访问
|
|
|
my_mod::public_function_in_crate();
|
|
|
|
|
|
// pub(in path) 项只能在指定的模块中访问
|
|
|
// 报错!函数 `public_function_in_my_mod` 是私有的
|
|
|
//my_mod::nested::public_function_in_my_mod();
|
|
|
// 试一试 ^ 取消该行的注释
|
|
|
|
|
|
// 模块的私有项不能直接访问,即便它是嵌套在公有模块内部的
|
|
|
|
|
|
// 报错!`private_function` 是私有的
|
|
|
//my_mod::private_function();
|
|
|
// 试一试 ^ 取消此行注释
|
|
|
|
|
|
// 报错!`private_function` 是私有的
|
|
|
//my_mod::nested::private_function();
|
|
|
// 试一试 ^ 取消此行的注释
|
|
|
|
|
|
// 报错! `private_nested` 是私有的
|
|
|
//my_mod::private_nested::function();
|
|
|
// 试一试 ^ 取消此行的注释
|
|
|
}</code></pre></pre>
|
|
|
<h2 id="课后练习"><a class="header" href="#课后练习">课后练习</a></h2>
|
|
|
<blockquote>
|
|
|
<p><a href="https://practice-zh.course.rs/crate-module/use-pub.html">Rust By Practice</a>,支持代码在线编辑和运行,并提供详细的<a href="https://github.com/sunface/rust-by-practice/blob/master/solutions/crate-module/use-pub.md">习题解答</a>。</p>
|
|
|
</blockquote>
|
|
|
|
|
|
<div id="giscus-container"></div>
|
|
|
</main>
|
|
|
|
|
|
<nav class="nav-wrapper" aria-label="Page navigation">
|
|
|
<!-- Mobile navigation buttons -->
|
|
|
<a rel="prev" href="../../basic/crate-module/module.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="../../basic/comment.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="../../basic/crate-module/module.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="../../basic/comment.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 = "basic/crate-module/use.md"
|
|
|
</script>
|
|
|
|
|
|
|
|
|
<!-- Custom JS scripts -->
|
|
|
<script src="../../assets/custom.js"></script>
|
|
|
<script src="../../assets/bigPicture.js"></script>
|
|
|
|
|
|
|
|
|
</div>
|
|
|
</body>
|
|
|
</html> |