255 lines
27 KiB
HTML
255 lines
27 KiB
HTML
|
<!DOCTYPE HTML>
|
|||
|
|
<html lang="en" class="sidebar-visible no-js light">
|
|||
|
|
<head>
|
|||
|
|
<!-- Book generated using mdBook -->
|
|||
|
|
<meta charset="UTF-8">
|
|||
|
|
<title>The Rust Programming Language - The Rust Programming Language</title>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
|
|||
|
|
<meta name="description" content="">
|
|||
|
|
<meta name="viewport" content="width=device-width, initial-scale=1">
|
|||
|
|
<meta name="theme-color" content="#ffffff" />
|
|||
|
|
|
|||
|
|
<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 href="googleFonts/css.css" rel="stylesheet" type="text/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="ferris.css">
|
|||
|
|
|
|||
|
|
<link rel="stylesheet" href="theme/2018-edition.css">
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
</head>
|
|||
|
|
<body>
|
|||
|
|
<!-- Provide site root to javascript -->
|
|||
|
|
<script type="text/javascript">
|
|||
|
|
var path_to_root = "";
|
|||
|
|
var default_theme = window.matchMedia("(prefers-color-scheme: dark)").matches ? "light" : "light";
|
|||
|
|
</script>
|
|||
|
|
|
|||
|
|
<!-- Work around some values being stored in localStorage wrapped in quotes -->
|
|||
|
|
<script type="text/javascript">
|
|||
|
|
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 type="text/javascript">
|
|||
|
|
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('no-js')
|
|||
|
|
html.classList.remove('light')
|
|||
|
|
html.classList.add(theme);
|
|||
|
|
html.classList.add('js');
|
|||
|
|
</script>
|
|||
|
|
|
|||
|
|
<!-- Hide / unhide sidebar before it is displayed -->
|
|||
|
|
<script type="text/javascript">
|
|||
|
|
var html = document.querySelector('html');
|
|||
|
|
var sidebar = 'hidden';
|
|||
|
|
if (document.body.clientWidth >= 1080) {
|
|||
|
|
try { sidebar = localStorage.getItem('mdbook-sidebar'); } catch(e) { }
|
|||
|
|
sidebar = sidebar || 'visible';
|
|||
|
|
}
|
|||
|
|
html.classList.remove('sidebar-visible');
|
|||
|
|
html.classList.add("sidebar-" + sidebar);
|
|||
|
|
</script>
|
|||
|
|
|
|||
|
|
<nav id="sidebar" class="sidebar" aria-label="Table of contents">
|
|||
|
|
<div id="sidebar-scrollbox" class="sidebar-scrollbox">
|
|||
|
|
<ol class="chapter"><li class="expanded affix "><a href="title-page.html">The Rust Programming Language</a></li><li class="expanded affix "><a href="foreword.html">Foreword</a></li><li class="expanded affix "><a href="ch00-00-introduction.html">Introduction</a></li><li class="expanded "><a href="ch01-00-getting-started.html"><strong aria-hidden="true">1.</strong> Getting Started</a></li><li><ol class="section"><li class="expanded "><a href="ch01-01-installation.html"><strong aria-hidden="true">1.1.</strong> Installation</a></li><li class="expanded "><a href="ch01-02-hello-world.html"><strong aria-hidden="true">1.2.</strong> Hello, World!</a></li><li class="expanded "><a href="ch01-03-hello-cargo.html"><strong aria-hidden="true">1.3.</strong> Hello, Cargo!</a></li></ol></li><li class="expanded "><a href="ch02-00-guessing-game-tutorial.html"><strong aria-hidden="true">2.</strong> Programming a Guessing Game</a></li><li class="expanded "><a href="ch03-00-common-programming-concepts.html"><strong aria-hidden="true">3.</strong> Common Programming Concepts</a></li><li><ol class="section"><li class="expanded "><a href="ch03-01-variables-and-mutability.html"><strong aria-hidden="true">3.1.</strong> Variables and Mutability</a></li><li class="expanded "><a href="ch03-02-data-types.html"><strong aria-hidden="true">3.2.</strong> Data Types</a></li><li class="expanded "><a href="ch03-03-how-functions-work.html"><strong aria-hidden="true">3.3.</strong> Functions</a></li><li class="expanded "><a href="ch03-04-comments.html"><strong aria-hidden="true">3.4.</strong> Comments</a></li><li class="expanded "><a href="ch03-05-control-flow.html"><strong aria-hidden="true">3.5.</strong> Control Flow</a></li></ol></li><li class="expanded "><a href="ch04-00-understanding-ownership.html"><strong aria-hidden="true">4.</strong> Understanding Ownership</a></li><li><ol class="section"><li class="expanded "><a href="ch04-01-what-is-ownership.html"><strong aria-hidden="true">4.1.</strong> What is Ownership?</a></li><li class="expanded "><a href="ch04-02-references-and-borrowing.html"><strong aria-hidden="true">4.2.</strong> References and Borrowing</a></li><li class="expanded "><a href="ch04-03-slices.html"><strong aria-hidden="true">4.3.</strong> The Slice Type</a></li></ol></li><li class="expanded "><a href="ch05-00-structs.html"><strong aria-hidden="true">5.</strong> Using Structs to Structure Related Data</a></li><li><ol class="section"><li class="expanded "><a href="ch05-01-defining-structs.html"><strong aria-hidden="true">5.1.</strong> Defining and Instantiating Structs</a></li><li class="expanded "><a href="ch05-02-example-structs.html"><strong aria-hidden="true">5.2.</strong> An Example Program Using Structs</a></li><li class="expanded "><a href="ch05-03-method-syntax.html"><strong aria-hidden="true">5.3.</strong> Method Syntax</a></li></ol></li><li class="expanded "><a href="ch06-00-enums.html"><strong aria-hidden="true">6.</strong> Enums and Pattern Matching</a></li><li><ol class="section"><li class="expanded "><a href="ch06-01-defining-an-enum.html"><strong aria-hidden="true">6.1.</strong> Defining an Enum</a></li><li class="expanded "><a href="ch06-02-match.html"><strong aria-hidden="true">6.2.</strong> The match Control Flow Operator</a></li><li class="expanded "><a href="ch06-03-if-let.html"><strong aria-hidden="true">6.3.</strong> Concise Control Flow with if let</a></li></ol></li><li class="expanded "><a href="ch07-00-managing-growing-projects-with-packages-crates-and-modules.html"><strong aria-hidden="true">7.</strong> Managing Growing Projects with Packages, Crates, and Modules</a></li><li><ol class="section"><li class="expanded "><a href="ch07-01-packages-and-crates.html"><strong aria-hidden="true">7.1.</strong> Packages and Crates</a></li><li class="expanded "><a href="ch07-02-defining-modules-to-control-scope-and-privacy.html"><strong aria-hidden="true">7.2.</strong> Defining Modules to Control Scope and Privacy</a></li><li class="expanded "><a href="ch07-03-paths-for-referring-to-an-item-in-the-module-tree.html"><
|
|||
|
|
</div>
|
|||
|
|
<div id="sidebar-resize-handle" class="sidebar-resize-handle"></div>
|
|||
|
|
</nav>
|
|||
|
|
|
|||
|
|
<div id="page-wrapper" class="page-wrapper">
|
|||
|
|
|
|||
|
|
<div class="page">
|
|||
|
|
|
|||
|
|
<div id="menu-bar" class="menu-bar">
|
|||
|
|
<div id="menu-bar-sticky-container">
|
|||
|
|
<div class="left-buttons">
|
|||
|
|
<button id="sidebar-toggle" class="icon-button" type="button" title="Toggle Table of Contents" aria-label="Toggle Table of Contents" aria-controls="sidebar">
|
|||
|
|
<i class="fa fa-bars"></i>
|
|||
|
|
</button>
|
|||
|
|
<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 (default)</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">The Rust Programming Language</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>
|
|||
|
|
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
</div>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<div id="search-wrapper" class="hidden">
|
|||
|
|
<form id="searchbar-outer" class="searchbar-outer">
|
|||
|
|
<input type="search" name="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 type="text/javascript">
|
|||
|
|
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">
|
|||
|
|
<main>
|
|||
|
|
<h1><a class="header" href="#the-rust-programming-language" id="the-rust-programming-language">The Rust Programming Language</a></h1>
|
|||
|
|
<p><em>by Steve Klabnik and Carol Nichols, with contributions from the Rust Community</em></p>
|
|||
|
|
<p>This version of the text assumes you’re using Rust 1.37.0 or later with
|
|||
|
|
<code>edition="2018"</code> in <em>Cargo.toml</em> of all projects to use Rust 2018 Edition
|
|||
|
|
idioms. See the <a href="ch01-01-installation.html">“Installation” section of Chapter 1</a><!-- ignore -->
|
|||
|
|
to install or update Rust, and see the new <a href="appendix-05-editions.html">Appendix E</a><!-- ignore
|
|||
|
|
--> for information on editions.</p>
|
|||
|
|
<p>The 2018 Edition of the Rust language includes a number of improvements that
|
|||
|
|
make Rust more ergonomic and easier to learn. This iteration of the book
|
|||
|
|
contains a number of changes to reflect those improvements:</p>
|
|||
|
|
<ul>
|
|||
|
|
<li>Chapter 7, “Managing Growing Projects with Packages, Crates, and Modules,”
|
|||
|
|
has been mostly rewritten. The module system and the way paths work in the
|
|||
|
|
2018 Edition were made more consistent.</li>
|
|||
|
|
<li>Chapter 10 has new sections titled “Traits as Parameters” and “Returning
|
|||
|
|
Types that Implement Traits” that explain the new <code>impl Trait</code> syntax.</li>
|
|||
|
|
<li>Chapter 11 has a new section titled “Using <code>Result<T, E></code> in Tests” that
|
|||
|
|
shows how to write tests that use the <code>?</code> operator.</li>
|
|||
|
|
<li>The “Advanced Lifetimes” section in Chapter 19 was removed because compiler
|
|||
|
|
improvements have made the constructs in that section even rarer.</li>
|
|||
|
|
<li>The previous Appendix D, “Macros,” has been expanded to include procedural
|
|||
|
|
macros and was moved to the “Macros” section in Chapter 19.</li>
|
|||
|
|
<li>Appendix A, “Keywords,” also explains the new raw identifiers feature that
|
|||
|
|
enables code written in the 2015 Edition and the 2018 Edition to interoperate.</li>
|
|||
|
|
<li>Appendix D is now titled “Useful Development Tools” and covers recently
|
|||
|
|
released tools that help you write Rust code.</li>
|
|||
|
|
<li>We fixed a number of small errors and imprecise wording throughout the book.
|
|||
|
|
Thank you to the readers who reported them!</li>
|
|||
|
|
</ul>
|
|||
|
|
<p>Note that any code in earlier iterations of <em>The Rust Programming Language</em>
|
|||
|
|
that compiled will continue to compile without <code>edition="2018"</code> in the
|
|||
|
|
project’s <em>Cargo.toml</em>, even as you update the Rust compiler version you’re
|
|||
|
|
using. That’s Rust’s backward compatibility guarantees at work!</p>
|
|||
|
|
<p>The HTML format is available online at
|
|||
|
|
<a href="https://doc.rust-lang.org/stable/book/">https://doc.rust-lang.org/stable/book/</a>
|
|||
|
|
and offline with installations of Rust made with <code>rustup</code>; run <code>rustup docs --book</code> to open.</p>
|
|||
|
|
<p>This text is available in <a href="https://nostarch.com/rust">paperback and ebook format from No Starch
|
|||
|
|
Press</a>.</p>
|
|||
|
|
|
|||
|
|
</main>
|
|||
|
|
|
|||
|
|
<nav class="nav-wrapper" aria-label="Page navigation">
|
|||
|
|
<!-- Mobile navigation buttons -->
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
<a rel="next" href="foreword.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 href="foreword.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 type="text/javascript">
|
|||
|
|
window.playpen_copyable = true;
|
|||
|
|
</script>
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
<script src="elasticlunr.min.js" type="text/javascript" charset="utf-8"></script>
|
|||
|
|
<script src="mark.min.js" type="text/javascript" charset="utf-8"></script>
|
|||
|
|
<script src="searcher.js" type="text/javascript" charset="utf-8"></script>
|
|||
|
|
|
|||
|
|
|
|||
|
|
<script src="clipboard.min.js" type="text/javascript" charset="utf-8"></script>
|
|||
|
|
<script src="highlight.js" type="text/javascript" charset="utf-8"></script>
|
|||
|
|
<script src="book.js" type="text/javascript" charset="utf-8"></script>
|
|||
|
|
|
|||
|
|
<!-- Custom JS scripts -->
|
|||
|
|
|
|||
|
|
<script type="text/javascript" src="ferris.js"></script>
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
|
|||
|
|
</body>
|
|||
|
|
</html>
|