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<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" class="active">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"><strong aria-hidden="true">7.3.</strong> Paths for Referring to an Item in the Module Tree</a></li><li class="expanded "><a href="ch07-04-bringing-paths-into-scope-with-the-use-keyword.html"><strong aria-hidden="true">7.4.</strong> Bringing Paths Into Scope with the use Keyword</a></li><li class="expanded "><a href="ch07-05-separating-modules-into-different-files.html"><strong aria-hidden="true">7.5.</strong> Separating Modules into Different Files</a></li></ol></li><li class="expanded "><a href="ch08-00-common-collections.html"><strong aria-hidden="true">8.</strong> Common Collections</a></li><li><ol class="section"><li class="expanded "><a href="ch08-01-vectors.html"><strong aria-hidden="true">8.1.</strong> Storing Lists of Values with Vectors</a></li><li class="expanded "><a href="ch08-02-strings.html"><strong aria-hidden="true">8.2.</strong> Storing UTF-8 Encoded Text with Strings</a></li><li class="expanded "><a href="ch08-03-hash-maps.html"><strong aria-hidden="true">8.3.</strong> Storing Keys with Associated Values in Hash Maps</a></li></ol></li><li class="expanded "><a href="ch09-00-error-handling.html"><strong aria-hidden="true">9.</strong> Error Handling</a></li><li><ol class="section"><li class="expanded "><a href="ch09-01-unrecoverable-errors-with-panic.html"><strong aria-hidden="true">9.1.</strong> Unrecoverable Errors with panic!</a></li><li class="expanded "><a href="ch09-02-recoverable-errors-with-result.html"><strong aria-hidden="true">9.2.</strong> Recoverable Errors with Result</a></li><li class="expanded "><a href="ch09-03-to-panic-or-not-to-panic.html"><strong aria-hidden="true">9.3.</strong> To panic! or Not To panic!</a></li></ol></li><li class="expanded "><a href="ch10-00-generics.html"><strong aria-hidden="true">10.</strong> Generic Types, Traits, and Lifetimes</a></li><li><ol class="section"><li class="expanded "><a href="ch10-01-syntax.html"><strong aria-hidden="true">10.1.</strong> Generic Data Types</a></li><li class="expanded "><a href="ch10-02-traits.html"><strong aria-hidden="true">10.2.</strong> Traits: Defining Shared Behavior</a></li><li class="expanded "><a href="ch10-03-lifetime-syntax.html"><strong aria-hidden="true">10.3.</strong> Validating References with Lifetimes</a></li></ol></li><li class="expanded "><a href="ch11-00-testing.html"><strong aria-hidden="true">11.</strong> Writing Automated Tests</a></li><li><ol class="section"><li class="expanded "><a href="ch11-01-writing-tests.html"><strong aria-hidden="true">11.1.</strong> How to Write Tests</a></li><li class="expanded "><a href="ch11-02-running-tests.html"><strong aria-hidden="true">11.2.</strong> Controlling How Tests Are Run</a></li><li class="expanded "><a href="ch11-03-test-organization.html"><strong aria-hidden="true">11.3.</strong> Test Organization</a></li></ol></li><li class="expanded "><a href="ch12-00-an-io-project.html"><strong aria-hidden="true">12.</strong> An I/O Project: Building a Command Line Program</a></li><li><ol class="section"><li class="expanded "><a href="ch12-01-accepting-command-line-arguments.html"><strong aria-hidden="true">12.1.</strong> Accepting Command Line Arguments</a></li><li class="expanded "><a href="ch12-02-reading-a-file.html"><strong aria-hidden="true">12.2.</strong> Reading a File</a></li><li class="expanded "><a href="ch12-03-improving-error-handling-and-modularity.html"><strong aria-hidden="true">12.3.</strong> Refactoring to Improve Modularity and Error Handling</a></li><li class="expanded "><a href="ch12-04-testing-the-librarys-functionality.html"><strong aria-hidden="true">12.4.</strong> Developing the Library’s Functionality with Test Driven Development</a></li><li class="expanded "><a href="ch12-05-working-with-environment-variables.html"><strong aria-hidden="true">12.5.</strong> Working with Environment Variables</a></li><li class="expanded "><a href="ch12-06-writing-to-stderr-instead-of-stdout.html"><strong aria-hidden="true">12.6.</strong> Writing Error Messages to Standard Error Instead of Standard Output</a></li></ol></li><li class="expanded "><a href="ch13-00-functional-features.html"><strong aria-hidden="true">13.</strong> Functional Language Features: Iterators and Closures</a></li><li><ol class="section"><li class="expanded "><a href="ch13-01-closures.html"><strong aria-hidden="true">13.1.</strong> Closures: Anonymous Functions that Can Capture Their Environment</a></li><li class="expanded "><a href="ch13-02-iterators.html"><strong aria-hidden="true">13.2.</strong> Processing a Series of Items with Iterators</a></li><li class="expanded "><a href="ch13-03-improving-our-io-project.html"><strong aria-hidden="true">13.3.</strong> Improving Our I/O Project</a></li><li class="expanded "><a href="ch13-04-performance.html"><strong aria-hidden="true">13.4.</strong> Comparing Performance: Loops vs. Iterators</a></li></ol></li><li class="expanded "><a href="ch14-00-more-about-cargo.html"><strong aria-hidden="true">14.</strong> More about Cargo and Crates.io</a></li><li><ol class="section"><li class="expanded "><a href="ch14-01-release-profiles.html"><strong aria-hidden="true">14.1.</strong> Customizing Builds with Release Profiles</a></li><li class="expanded "><a href="ch14-02-publishing-to-crates-io.html"><strong aria-hidden="true">14.2.</strong> Publishing a Crate to Crates.io</a></li><li class="expanded "><a href="ch14-03-cargo-workspaces.html"><strong aria-hidden="true">14.3.</strong> Cargo Workspaces</a></li><li class="expanded "><a href="ch14-04-installing-binaries.html"><strong aria-hidden="true">14.4.</strong> Installing Binaries from Crates.io with cargo install</a></li><li class="expanded "><a href="ch14-05-extending-cargo.html"><strong aria-hidden="true">14.5.</strong> Extending Cargo with Custom Commands</a></li></ol></li><li class="expanded "><a href="ch15-00-smart-pointers.html"><strong aria-hidden="true">15.</strong> Smart Pointers</a></li><li><ol class="section"><li class="expanded "><a href="ch15-01-box.html"><strong aria-hidden="true">15.1.</strong> Using Box<T> to Point to Data on the Heap</a></li><li class="expanded "><a href="ch15-02-deref.html"><strong aria-hidden="true">15.2.</strong> Treating Smart Pointers Like Regular References with the Deref Trait</a></li><li class="expanded "><a href="ch15-03-drop.html"><strong aria-hidden="true">15.3.</strong> Running Code on Cleanup with the Drop Trait</a></li><li class="expanded "><a href="ch15-04-rc.html"><strong aria-hidden="true">15.4.</strong> Rc<T>, the Reference Counted Smart Pointer</a></li><li class="expanded "><a href="ch15-05-interior-mutability.html"><strong aria-hidden="true">15.5.</strong> RefCell<T> and the Interior Mutability Pattern</a></li><li class="expanded "><a href="ch15-06-reference-cycles.html"><strong aria-hidden="true">15.6.</strong> Reference Cycles Can Leak Memory</a></li></ol></li><li class="expanded "><a href="ch16-00-concurrency.html"><strong aria-hidden="true">16.</strong> Fearless Concurrency</a></li><li><ol class="section"><li class="expanded "><a href="ch16-01-threads.html"><strong aria-hidden="true">16.1.</strong> Using Threads to Run Code Simultaneously</a></li><li class="expanded "><a href="ch16-02-message-passing.html"><strong aria-hidden="true">16.2.</strong> Using Message Passing to Transfer Data Between Threads</a></li><li class="expanded "><a href="ch16-03-shared-state.html"><strong aria-hidden="true">16.3.</strong> Shared-State Concurrency</a></li><li class="expanded "><a href="ch16-04-extensible-concurrency-sync-and-send.html"><strong aria-hidden="true">16.4.</strong> Extensible Concurrency with the Sync and Send Traits</a></li></ol></li><li class="expanded "><a href="ch17-00-oop.html"><strong aria-hidden="true">17.</strong> Object Oriented Programming Features of Rust</a></li><li><ol class="section"><li class="expanded "><a href="ch17-01-what-is-oo.html"><strong aria-hidden="true">17.1.</strong> Characteristics of Object-Oriented Languages</a></li><li class="expanded "><a href="ch17-02-trait-objects.html"><strong aria-hidden="true">17.2.</strong> Using Trait Objects That Allow for Values of Different Types</a></li><li class="expanded "><a href="ch17-03-oo-design-patterns.html"><strong aria-hidden="true">17.3.</strong> Implementing an Object-Oriented Design Pattern</a></li></ol></li><li class="expanded "><a href="ch18-00-patterns.html"><strong aria-hidden="true">18.</strong> Patterns and Matching</a></li><li><ol class="section"><li class="expanded "><a href="ch18-01-all-the-places-for-patterns.html"><strong aria-hidden="true">18.1.</strong> All the Places Patterns Can Be Used</a></li><li class="expanded "><a href="ch18-02-refutability.html"><strong aria-hidden="true">18.2.</strong> Refutability: Whether a Pattern Might Fail to Match</a></li><li class="expanded "><a href="ch18-03-pattern-syntax.html"><strong aria-hidden="true">18.3.</strong> Pattern Syntax</a></li></ol></li><li class="expanded "><a href="ch19-00-advanced-features.html"><strong aria-hidden="true">19.</strong> Advanced Features</a></li><li><ol class="section"><li class="expanded "><a href="ch19-01-unsafe-rust.html"><strong aria-hidden="true">19.1.</strong> Unsafe Rust</a></li><li class="expanded "><a href="ch19-03-advanced-traits.html"><strong aria-hidden="true">19.2.</strong> Advanced Traits</a></li><li class="expanded "><a href="ch19-04-advanced-types.html"><strong aria-hidden="true">19.3.</strong> Advanced Types</a></li><li class="expanded "><a href="ch19-05-advanced-functions-and-closures.html"><strong aria-hidden="true">19.4.</strong> Advanced Functions and Closures</a></li><li class="expanded "><a href="ch19-06-macros.html"><strong aria-hidden="true">19.5.</strong> Macros</a></li></ol></li><li class="expanded "><a href="ch20-00-final-project-a-web-server.html"><strong aria-hidden="true">20.</strong> Final Project: Building a Multithreaded Web Server</a></li><li><ol class="section"><li class="expanded "><a href="ch20-01-single-threaded.html"><strong aria-hidden="true">20.1.</strong> Building a Single-Threaded Web Server</a></li><li class="expanded "><a href="ch20-02-multithreaded.html"><strong aria-hidden="true">20.2.</strong> Turning Our Single-Threaded Server into a Multithreaded Server</a></li><li class="expanded "><a href="ch20-03-graceful-shutdown-and-cleanup.html"><strong aria-hidden="true">20.3.</strong> Graceful Shutdown and Cleanup</a></li></ol></li><li class="expanded "><a href="appendix-00.html"><strong aria-hidden="true">21.</strong> Appendix</a></li><li><ol class="section"><li class="expanded "><a href="appendix-01-keywords.html"><strong aria-hidden="true">21.1.</strong> A - Keywords</a></li><li class="expanded "><a href="appendix-02-operators.html"><strong aria-hidden="true">21.2.</strong> B - Operators and Symbols</a></li><li class="expanded "><a href="appendix-03-derivable-traits.html"><strong aria-hidden="true">21.3.</strong> C - Derivable Traits</a></li><li class="expanded "><a href="appendix-04-useful-development-tools.html"><strong aria-hidden="true">21.4.</strong> D - Useful Development Tools</a></li><li class="expanded "><a href="appendix-05-editions.html"><strong aria-hidden="true">21.5.</strong> E - Editions</a></li><li class="expanded "><a href="appendix-06-translation.html"><strong aria-hidden="true">21.6.</strong> F - Translations of the Book</a></li><li class="expanded "><a href="appendix-07-nightly-rust.html"><strong aria-hidden="true">21.7.</strong> G - How Rust is Made and “Nightly Rust”</a></li></ol></li></ol>
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<h1 class="menu-title">The Rust Programming Language</h1>
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<h1><a class="header" href="#introduction" id="introduction">Introduction</a></h1>
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<blockquote>
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<p>Note: This edition of the book is the same as <a href="https://nostarch.com/rust">The Rust Programming
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Language</a> available in print and ebook format from <a href="https://nostarch.com/">No Starch
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<p>Welcome to <em>The Rust Programming Language</em>, an introductory book about Rust.
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The Rust programming language helps you write faster, more reliable software.
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High-level ergonomics and low-level control are often at odds in programming
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language design; Rust challenges that conflict. Through balancing powerful
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technical capacity and a great developer experience, Rust gives you the option
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to control low-level details (such as memory usage) without all the hassle
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traditionally associated with such control.</p>
|
||
<h2><a class="header" href="#who-rust-is-for" id="who-rust-is-for">Who Rust Is For</a></h2>
|
||
<p>Rust is ideal for many people for a variety of reasons. Let’s look at a few of
|
||
the most important groups.</p>
|
||
<h3><a class="header" href="#teams-of-developers" id="teams-of-developers">Teams of Developers</a></h3>
|
||
<p>Rust is proving to be a productive tool for collaborating among large teams of
|
||
developers with varying levels of systems programming knowledge. Low-level code
|
||
is prone to a variety of subtle bugs, which in most other languages can be
|
||
caught only through extensive testing and careful code review by experienced
|
||
developers. In Rust, the compiler plays a gatekeeper role by refusing to
|
||
compile code with these elusive bugs, including concurrency bugs. By working
|
||
alongside the compiler, the team can spend their time focusing on the program’s
|
||
logic rather than chasing down bugs.</p>
|
||
<p>Rust also brings contemporary developer tools to the systems programming world:</p>
|
||
<ul>
|
||
<li>Cargo, the included dependency manager and build tool, makes adding,
|
||
compiling, and managing dependencies painless and consistent across the Rust
|
||
ecosystem.</li>
|
||
<li>Rustfmt ensures a consistent coding style across developers.</li>
|
||
<li>The Rust Language Server powers Integrated Development Environment (IDE)
|
||
integration for code completion and inline error messages.</li>
|
||
</ul>
|
||
<p>By using these and other tools in the Rust ecosystem, developers can be
|
||
productive while writing systems-level code.</p>
|
||
<h3><a class="header" href="#students" id="students">Students</a></h3>
|
||
<p>Rust is for students and those who are interested in learning about systems
|
||
concepts. Using Rust, many people have learned about topics like operating
|
||
systems development. The community is very welcoming and happy to answer
|
||
student questions. Through efforts such as this book, the Rust teams want to
|
||
make systems concepts more accessible to more people, especially those new to
|
||
programming.</p>
|
||
<h3><a class="header" href="#companies" id="companies">Companies</a></h3>
|
||
<p>Hundreds of companies, large and small, use Rust in production for a variety of
|
||
tasks. Those tasks include command line tools, web services, DevOps tooling,
|
||
embedded devices, audio and video analysis and transcoding, cryptocurrencies,
|
||
bioinformatics, search engines, Internet of Things applications, machine
|
||
learning, and even major parts of the Firefox web browser.</p>
|
||
<h3><a class="header" href="#open-source-developers" id="open-source-developers">Open Source Developers</a></h3>
|
||
<p>Rust is for people who want to build the Rust programming language, community,
|
||
developer tools, and libraries. We’d love to have you contribute to the Rust
|
||
language.</p>
|
||
<h3><a class="header" href="#people-who-value-speed-and-stability" id="people-who-value-speed-and-stability">People Who Value Speed and Stability</a></h3>
|
||
<p>Rust is for people who crave speed and stability in a language. By speed, we
|
||
mean the speed of the programs that you can create with Rust and the speed at
|
||
which Rust lets you write them. The Rust compiler’s checks ensure stability
|
||
through feature additions and refactoring. This is in contrast to the brittle
|
||
legacy code in languages without these checks, which developers are often
|
||
afraid to modify. By striving for zero-cost abstractions, higher-level features
|
||
that compile to lower-level code as fast as code written manually, Rust
|
||
endeavors to make safe code be fast code as well.</p>
|
||
<p>The Rust language hopes to support many other users as well; those mentioned
|
||
here are merely some of the biggest stakeholders. Overall, Rust’s greatest
|
||
ambition is to eliminate the trade-offs that programmers have accepted for
|
||
decades by providing safety <em>and</em> productivity, speed <em>and</em> ergonomics. Give
|
||
Rust a try and see if its choices work for you.</p>
|
||
<h2><a class="header" href="#who-this-book-is-for" id="who-this-book-is-for">Who This Book Is For</a></h2>
|
||
<p>This book assumes that you’ve written code in another programming language but
|
||
doesn’t make any assumptions about which one. We’ve tried to make the material
|
||
broadly accessible to those from a wide variety of programming backgrounds. We
|
||
don’t spend a lot of time talking about what programming <em>is</em> or how to think
|
||
about it. If you’re entirely new to programming, you would be better served by
|
||
reading a book that specifically provides an introduction to programming.</p>
|
||
<h2><a class="header" href="#how-to-use-this-book" id="how-to-use-this-book">How to Use This Book</a></h2>
|
||
<p>In general, this book assumes that you’re reading it in sequence from front to
|
||
back. Later chapters build on concepts in earlier chapters, and earlier
|
||
chapters might not delve into details on a topic; we typically revisit the
|
||
topic in a later chapter.</p>
|
||
<p>You’ll find two kinds of chapters in this book: concept chapters and project
|
||
chapters. In concept chapters, you’ll learn about an aspect of Rust. In project
|
||
chapters, we’ll build small programs together, applying what you’ve learned so
|
||
far. Chapters 2, 12, and 20 are project chapters; the rest are concept chapters.</p>
|
||
<p>Chapter 1 explains how to install Rust, how to write a “Hello, world!” program,
|
||
and how to use Cargo, Rust’s package manager and build tool. Chapter 2 is a
|
||
hands-on introduction to the Rust language. Here we cover concepts at a high
|
||
level, and later chapters will provide additional detail. If you want to get
|
||
your hands dirty right away, Chapter 2 is the place for that. At first, you
|
||
might even want to skip Chapter 3, which covers Rust features similar to those
|
||
of other programming languages, and head straight to Chapter 4 to learn about
|
||
Rust’s ownership system. However, if you’re a particularly meticulous learner
|
||
who prefers to learn every detail before moving on to the next, you might want
|
||
to skip Chapter 2 and go straight to Chapter 3, returning to Chapter 2 when
|
||
you’d like to work on a project applying the details you’ve learned.</p>
|
||
<p>Chapter 5 discusses structs and methods, and Chapter 6 covers enums, <code>match</code>
|
||
expressions, and the <code>if let</code> control flow construct. You’ll use structs and
|
||
enums to make custom types in Rust.</p>
|
||
<p>In Chapter 7, you’ll learn about Rust’s module system and about privacy rules
|
||
for organizing your code and its public Application Programming Interface
|
||
(API). Chapter 8 discusses some common collection data structures that the
|
||
standard library provides, such as vectors, strings, and hash maps. Chapter 9
|
||
explores Rust’s error-handling philosophy and techniques.</p>
|
||
<p>Chapter 10 digs into generics, traits, and lifetimes, which give you the power
|
||
to define code that applies to multiple types. Chapter 11 is all about testing,
|
||
which even with Rust’s safety guarantees is necessary to ensure your program’s
|
||
logic is correct. In Chapter 12, we’ll build our own implementation of a subset
|
||
of functionality from the <code>grep</code> command line tool that searches for text
|
||
within files. For this, we’ll use many of the concepts we discussed in the
|
||
previous chapters.</p>
|
||
<p>Chapter 13 explores closures and iterators: features of Rust that come from
|
||
functional programming languages. In Chapter 14, we’ll examine Cargo in more
|
||
depth and talk about best practices for sharing your libraries with others.
|
||
Chapter 15 discusses smart pointers that the standard library provides and the
|
||
traits that enable their functionality.</p>
|
||
<p>In Chapter 16, we’ll walk through different models of concurrent programming
|
||
and talk about how Rust helps you to program in multiple threads fearlessly.
|
||
Chapter 17 looks at how Rust idioms compare to object-oriented programming
|
||
principles you might be familiar with.</p>
|
||
<p>Chapter 18 is a reference on patterns and pattern matching, which are powerful
|
||
ways of expressing ideas throughout Rust programs. Chapter 19 contains a
|
||
smorgasbord of advanced topics of interest, including unsafe Rust, macros, and
|
||
more about lifetimes, traits, types, functions, and closures.</p>
|
||
<p>In Chapter 20, we’ll complete a project in which we’ll implement a low-level
|
||
multithreaded web server!</p>
|
||
<p>Finally, some appendixes contain useful information about the language in a
|
||
more reference-like format. Appendix A covers Rust’s keywords, Appendix B
|
||
covers Rust’s operators and symbols, Appendix C covers derivable traits
|
||
provided by the standard library, Appendix D covers some useful development
|
||
tools, and Appendix E explains Rust editions.</p>
|
||
<p>There is no wrong way to read this book: if you want to skip ahead, go for it!
|
||
You might have to jump back to earlier chapters if you experience any
|
||
confusion. But do whatever works for you.</p>
|
||
<p><span id="ferris"></span></p>
|
||
<p>An important part of the process of learning Rust is learning how to read the
|
||
error messages the compiler displays: these will guide you toward working code.
|
||
As such, we’ll provide many examples that don’t compile along with the error
|
||
message the compiler will show you in each situation. Know that if you enter
|
||
and run a random example, it may not compile! Make sure you read the
|
||
surrounding text to see whether the example you’re trying to run is meant to
|
||
error. Ferris will also help you distinguish code that isn’t meant to work:</p>
|
||
<table><thead><tr><th>Ferris</th><th>Meaning</th></tr></thead><tbody>
|
||
<tr><td><img src="img/ferris/does_not_compile.svg" class="ferris-explain"/></td><td>This code does not compile!</td></tr>
|
||
<tr><td><img src="img/ferris/panics.svg" class="ferris-explain"/></td><td>This code panics!</td></tr>
|
||
<tr><td><img src="img/ferris/unsafe.svg" class="ferris-explain"/></td><td>This code block contains unsafe code.</td></tr>
|
||
<tr><td><img src="img/ferris/not_desired_behavior.svg" class="ferris-explain"/></td><td>This code does not produce the desired behavior.</td></tr>
|
||
</tbody></table>
|
||
<p>In most situations, we’ll lead you to the correct version of any code that
|
||
doesn’t compile.</p>
|
||
<h2><a class="header" href="#source-code" id="source-code">Source Code</a></h2>
|
||
<p>The source files from which this book is generated can be found on
|
||
<a href="https://github.com/rust-lang/book/tree/master/src">GitHub</a>.</p>
|
||
|
||
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