mirror of
https://github.com/Dhghomon/easy_rust
synced 2024-11-03 15:40:22 +00:00
407 lines
24 KiB
HTML
407 lines
24 KiB
HTML
<!DOCTYPE HTML>
|
|
<html lang="en" class="sidebar-visible no-js light">
|
|
<head>
|
|
<!-- Book generated using mdBook -->
|
|
<meta charset="UTF-8">
|
|
<title> Box around traits - Easy Rust</title>
|
|
|
|
|
|
|
|
|
|
<!-- Custom HTML head -->
|
|
|
|
|
|
|
|
<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="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 -->
|
|
|
|
|
|
|
|
</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 ? "navy" : "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 class="sidebar-scrollbox">
|
|
<ol class="chapter"><li class="chapter-item expanded "><a href="Chapter_0.html"><strong aria-hidden="true">1.</strong> Update</a></li><li class="chapter-item expanded "><a href="Chapter_1.html"><strong aria-hidden="true">2.</strong> Introduction</a></li><li class="chapter-item expanded "><a href="Chapter_2.html"><strong aria-hidden="true">3.</strong> Who am I?</a></li><li class="chapter-item expanded "><a href="Chapter_3.html"><strong aria-hidden="true">4.</strong> Writing Rust in Easy English</a></li><li class="chapter-item expanded "><a href="Chapter_4.html"><strong aria-hidden="true">5.</strong> Rust Playground</a></li><li class="chapter-item expanded "><a href="Chapter_5.html"><strong aria-hidden="true">6.</strong> 🚧 and ⚠️</a></li><li class="chapter-item expanded "><a href="Chapter_6.html"><strong aria-hidden="true">7.</strong> Comments</a></li><li class="chapter-item expanded "><a href="Chapter_7.html"><strong aria-hidden="true">8.</strong> Types</a></li><li class="chapter-item expanded "><a href="Chapter_8.html"><strong aria-hidden="true">9.</strong> Type inference</a></li><li class="chapter-item expanded "><a href="Chapter_9.html"><strong aria-hidden="true">10.</strong> Printing 'hello, world!'</a></li><li class="chapter-item expanded "><a href="Chapter_10.html"><strong aria-hidden="true">11.</strong> Display and debug</a></li><li class="chapter-item expanded "><a href="Chapter_11.html"><strong aria-hidden="true">12.</strong> Mutability (changing)</a></li><li class="chapter-item expanded "><a href="Chapter_12.html"><strong aria-hidden="true">13.</strong> The stack, the heap, and pointers</a></li><li class="chapter-item expanded "><a href="Chapter_13.html"><strong aria-hidden="true">14.</strong> More about printing</a></li><li class="chapter-item expanded "><a href="Chapter_14.html"><strong aria-hidden="true">15.</strong> Strings</a></li><li class="chapter-item expanded "><a href="Chapter_15.html"><strong aria-hidden="true">16.</strong> const and static</a></li><li class="chapter-item expanded "><a href="Chapter_16.html"><strong aria-hidden="true">17.</strong> More on references</a></li><li class="chapter-item expanded "><a href="Chapter_17.html"><strong aria-hidden="true">18.</strong> Mutable references</a></li><li class="chapter-item expanded "><a href="Chapter_18.html"><strong aria-hidden="true">19.</strong> Giving references to functions</a></li><li class="chapter-item expanded "><a href="Chapter_19.html"><strong aria-hidden="true">20.</strong> Copy types</a></li><li class="chapter-item expanded "><a href="Chapter_20.html"><strong aria-hidden="true">21.</strong> Collection types</a></li><li class="chapter-item expanded "><a href="Chapter_21.html"><strong aria-hidden="true">22.</strong> Vectors</a></li><li class="chapter-item expanded "><a href="Chapter_22.html"><strong aria-hidden="true">23.</strong> Tuples</a></li><li class="chapter-item expanded "><a href="Chapter_23.html"><strong aria-hidden="true">24.</strong> Control flow</a></li><li class="chapter-item expanded "><a href="Chapter_24.html"><strong aria-hidden="true">25.</strong> Structs</a></li><li class="chapter-item expanded "><a href="Chapter_25.html"><strong aria-hidden="true">26.</strong> Enums</a></li><li class="chapter-item expanded "><a href="Chapter_26.html"><strong aria-hidden="true">27.</strong> Loops</a></li><li class="chapter-item expanded "><a href="Chapter_27.html"><strong aria-hidden="true">28.</strong> Implementing structs and enums</a></li><li class="chapter-item expanded "><a href="Chapter_28.html"><strong aria-hidden="true">29.</strong> Destructuring</a></li><li class="chapter-item expanded "><a href="Chapter_29.html"><strong aria-hidden="true">30.</strong> References and the dot operator</a></li><li class="chapter-item expanded "><a href="Chapter_30.html"><strong aria-hidden="true">31.</strong> Generics</a></li><li class="chapter-item expanded "><a href="Chapter_31.html"><strong aria-hidden="true">32.</strong> Option and Result</a></li><li class="chapter-item expanded "><a href="Chapter_32.html"><strong aria-hidden="true">33.</strong> Other collections</a></li><li class="chapter-item expanded "><a href="Chapter_33.html"><strong aria-hidden="true">34.</strong> The ? operator</a></li><li class="chapter-item expanded "><a href="Chapter_34.html"><strong aria-hidden="true">35.</strong> Traits</a></li><li class="chapter-item expanded "><a href="Chapter_35.html"><strong aria-hidden="true">36.</strong> Chaining methods</a></li><li class="chapter-item expanded "><a href="Chapter_36.html"><strong aria-hidden="true">37.</strong> Iterators</a></li><li class="chapter-item expanded "><a href="Chapter_37.html"><strong aria-hidden="true">38.</strong> Closures</a></li><li class="chapter-item expanded "><a href="Chapter_38.html"><strong aria-hidden="true">39.</strong> The dbg! macro and .inspect</a></li><li class="chapter-item expanded "><a href="Chapter_39.html"><strong aria-hidden="true">40.</strong> Types of &str</a></li><li class="chapter-item expanded "><a href="Chapter_40.html"><strong aria-hidden="true">41.</strong> Lifetimes</a></li><li class="chapter-item expanded "><a href="Chapter_41.html"><strong aria-hidden="true">42.</strong> Interior mutability</a></li><li class="chapter-item expanded "><a href="Chapter_42.html"><strong aria-hidden="true">43.</strong> Cow</a></li><li class="chapter-item expanded "><a href="Chapter_43.html"><strong aria-hidden="true">44.</strong> Type aliases</a></li><li class="chapter-item expanded "><a href="Chapter_44.html"><strong aria-hidden="true">45.</strong> The todo! macro</a></li><li class="chapter-item expanded "><a href="Chapter_45.html"><strong aria-hidden="true">46.</strong> Rc</a></li><li class="chapter-item expanded "><a href="Chapter_46.html"><strong aria-hidden="true">47.</strong> Multiple threads</a></li><li class="chapter-item expanded "><a href="Chapter_47.html"><strong aria-hidden="true">48.</strong> Closures in functions</a></li><li class="chapter-item expanded "><a href="Chapter_48.html"><strong aria-hidden="true">49.</strong> impl Trait</a></li><li class="chapter-item expanded "><a href="Chapter_49.html"><strong aria-hidden="true">50.</strong> Arc</a></li><li class="chapter-item expanded "><a href="Chapter_50.html"><strong aria-hidden="true">51.</strong> Channels</a></li><li class="chapter-item expanded "><a href="Chapter_51.html"><strong aria-hidden="true">52.</strong> Reading Rust documentation</a></li><li class="chapter-item expanded "><a href="Chapter_52.html"><strong aria-hidden="true">53.</strong> Attributes</a></li><li class="chapter-item expanded "><a href="Chapter_53.html"><strong aria-hidden="true">54.</strong> Box</a></li><li class="chapter-item expanded "><a href="Chapter_54.html" class="active"><strong aria-hidden="true">55.</strong> Box around traits</a></li><li class="chapter-item expanded "><a href="Chapter_55.html"><strong aria-hidden="true">56.</strong> Default and the builder pattern</a></li><li class="chapter-item expanded "><a href="Chapter_56.html"><strong aria-hidden="true">57.</strong> Deref and DerefMut</a></li><li class="chapter-item expanded "><a href="Chapter_57.html"><strong aria-hidden="true">58.</strong> Crates and modules</a></li><li class="chapter-item expanded "><a href="Chapter_58.html"><strong aria-hidden="true">59.</strong> Testing</a></li><li class="chapter-item expanded "><a href="Chapter_59.html"><strong aria-hidden="true">60.</strong> External crates</a></li><li class="chapter-item expanded "><a href="Chapter_60.html"><strong aria-hidden="true">61.</strong> A tour of the standard library</a></li><li class="chapter-item expanded "><a href="Chapter_61.html"><strong aria-hidden="true">62.</strong> Writing macros</a></li><li class="chapter-item expanded "><a href="Chapter_62.html"><strong aria-hidden="true">63.</strong> cargo</a></li><li class="chapter-item expanded "><a href="Chapter_63.html"><strong aria-hidden="true">64.</strong> Taking user input</a></li><li class="chapter-item expanded "><a href="Chapter_64.html"><strong aria-hidden="true">65.</strong> Using files</a></li><li class="chapter-item expanded "><a href="Chapter_65.html"><strong aria-hidden="true">66.</strong> cargo doc</a></li><li class="chapter-item expanded "><a href="Chapter_66.html"><strong aria-hidden="true">67.</strong> The end?</a></li></ol>
|
|
</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-hover-placeholder"></div>
|
|
<div id="menu-bar" class="menu-bar sticky bordered">
|
|
<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">Easy Rust</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 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>
|
|
<h2 id="box-around-traits"><a class="header" href="#box-around-traits">Box around traits</a></h2>
|
|
<p><code>Box</code> is very useful for returning traits. You know that you can write traits in generic functions like in this example:</p>
|
|
<pre><pre class="playground"><code class="language-rust">use std::fmt::Display;
|
|
|
|
struct DoesntImplementDisplay {}
|
|
|
|
fn displays_it<T: Display>(input: T) {
|
|
println!("{}", input);
|
|
}
|
|
|
|
fn main() {}
|
|
</code></pre></pre>
|
|
<p>This only takes something with <code>Display</code>, so it can't accept our struct <code>DoesntImplementDisplay</code>. But it can take in a lot of others like <code>String</code>.</p>
|
|
<p>You also saw that we can use <code>impl Trait</code> to return other traits, or closures. <code>Box</code> can be used in a similar way. You can use a <code>Box</code> because otherwise the compiler won't know the size of the value. This example shows that a trait can be used on something of any size:</p>
|
|
<pre><pre class="playground"><code class="language-rust">#![allow(dead_code)] // Tell the compiler to be quiet
|
|
use std::mem::size_of; // This gives the size of a type
|
|
|
|
trait JustATrait {} // We will implement this on everything
|
|
|
|
enum EnumOfNumbers {
|
|
I8(i8),
|
|
AnotherI8(i8),
|
|
OneMoreI8(i8),
|
|
}
|
|
impl JustATrait for EnumOfNumbers {}
|
|
|
|
struct StructOfNumbers {
|
|
an_i8: i8,
|
|
another_i8: i8,
|
|
one_more_i8: i8,
|
|
}
|
|
impl JustATrait for StructOfNumbers {}
|
|
|
|
enum EnumOfOtherTypes {
|
|
I8(i8),
|
|
AnotherI8(i8),
|
|
Collection(Vec<String>),
|
|
}
|
|
impl JustATrait for EnumOfOtherTypes {}
|
|
|
|
struct StructOfOtherTypes {
|
|
an_i8: i8,
|
|
another_i8: i8,
|
|
a_collection: Vec<String>,
|
|
}
|
|
impl JustATrait for StructOfOtherTypes {}
|
|
|
|
struct ArrayAndI8 {
|
|
array: [i8; 1000], // This one will be very large
|
|
an_i8: i8,
|
|
in_u8: u8,
|
|
}
|
|
impl JustATrait for ArrayAndI8 {}
|
|
|
|
fn main() {
|
|
println!(
|
|
"{}, {}, {}, {}, {}",
|
|
size_of::<EnumOfNumbers>(),
|
|
size_of::<StructOfNumbers>(),
|
|
size_of::<EnumOfOtherTypes>(),
|
|
size_of::<StructOfOtherTypes>(),
|
|
size_of::<ArrayAndI8>(),
|
|
);
|
|
}
|
|
</code></pre></pre>
|
|
<p>When we print the size of these, we get <code>2, 3, 32, 32, 1002</code>. So if you were to do this, it would give an error:</p>
|
|
<pre><pre class="playground"><code class="language-rust">
|
|
<span class="boring">#![allow(unused)]
|
|
</span><span class="boring">fn main() {
|
|
</span>// ⚠️
|
|
fn returns_just_a_trait() -> JustATrait {
|
|
let some_enum = EnumOfNumbers::I8(8);
|
|
some_enum
|
|
}
|
|
<span class="boring">}
|
|
</span></code></pre></pre>
|
|
<p>It says:</p>
|
|
<pre><code class="language-text">error[E0746]: return type cannot have an unboxed trait object
|
|
--> src\main.rs:53:30
|
|
|
|
|
53 | fn returns_just_a_trait() -> JustATrait {
|
|
| ^^^^^^^^^^ doesn't have a size known at compile-time
|
|
</code></pre>
|
|
<p>And this is true, because the size could be 2, 3, 32, 1002, or anything else. So we put it in a <code>Box</code> instead. Here we also add the keyword <code>dyn</code>. <code>dyn</code> is a word that shows you that you are talking about a trait, not a struct or anything else.</p>
|
|
<p>So you can change the function to this:</p>
|
|
<pre><pre class="playground"><code class="language-rust">
|
|
<span class="boring">#![allow(unused)]
|
|
</span><span class="boring">fn main() {
|
|
</span>// 🚧
|
|
fn returns_just_a_trait() -> Box<dyn JustATrait> {
|
|
let some_enum = EnumOfNumbers::I8(8);
|
|
Box::new(some_enum)
|
|
}
|
|
<span class="boring">}
|
|
</span></code></pre></pre>
|
|
<p>And now it works, because on the stack is just a <code>Box</code> and we know the size of <code>Box</code>.</p>
|
|
<p>You see this a lot in the form <code>Box<dyn Error></code>, because sometimes you can have more than one possible error.</p>
|
|
<p>We can quickly create two error types to show this. To make an official error type, you have to implement <code>std::error::Error</code> for it. That part is easy: just write impl <code>std::error::Error {}</code>. But errors also need <code>Debug</code> and <code>Display</code> so they can give information on the problem. <code>Debug</code> is easy with <code>#[derive(Debug)]</code> but <code>Display</code> needs the <code>.fmt()</code> method. We did this once before.</p>
|
|
<p>The code looks like this:</p>
|
|
<pre><pre class="playground"><code class="language-rust">use std::error::Error;
|
|
use std::fmt;
|
|
|
|
#[derive(Debug)]
|
|
struct ErrorOne;
|
|
|
|
impl Error for ErrorOne {} // Now it is an error type with Debug. Time for Display:
|
|
|
|
impl fmt::Display for ErrorOne {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
write!(f, "You got the first error!") // All it does is write this message
|
|
}
|
|
}
|
|
|
|
|
|
#[derive(Debug)] // Do the same thing with ErrorTwo
|
|
struct ErrorTwo;
|
|
|
|
impl Error for ErrorTwo {}
|
|
|
|
impl fmt::Display for ErrorTwo {
|
|
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
write!(f, "You got the second error!")
|
|
}
|
|
}
|
|
|
|
// Make a function that just returns a String or an error
|
|
fn returns_errors(input: u8) -> Result<String, Box<dyn Error>> { // With Box<dyn Error> you can return anything that has the Error trait
|
|
|
|
match input {
|
|
0 => Err(Box::new(ErrorOne)), // Don't forget to put it in a box
|
|
1 => Err(Box::new(ErrorTwo)),
|
|
_ => Ok("Looks fine to me".to_string()), // This is the success type
|
|
}
|
|
|
|
}
|
|
|
|
fn main() {
|
|
|
|
let vec_of_u8s = vec![0_u8, 1, 80]; // Three numbers to try out
|
|
|
|
for number in vec_of_u8s {
|
|
match returns_errors(number) {
|
|
Ok(input) => println!("{}", input),
|
|
Err(message) => println!("{}", message),
|
|
}
|
|
}
|
|
}
|
|
</code></pre></pre>
|
|
<p>This will print:</p>
|
|
<pre><code class="language-text">You got the first error!
|
|
You got the second error!
|
|
Looks fine to me
|
|
</code></pre>
|
|
<p>If we didn't have a <code>Box<dyn Error></code> and wrote this, we would have a problem:</p>
|
|
<pre><pre class="playground"><code class="language-rust">
|
|
<span class="boring">#![allow(unused)]
|
|
</span><span class="boring">fn main() {
|
|
</span>// ⚠️
|
|
fn returns_errors(input: u8) -> Result<String, Error> {
|
|
match input {
|
|
0 => Err(ErrorOne),
|
|
1 => Err(ErrorTwo),
|
|
_ => Ok("Looks fine to me".to_string()),
|
|
}
|
|
}
|
|
<span class="boring">}
|
|
</span></code></pre></pre>
|
|
<p>It will tell you:</p>
|
|
<pre><code class="language-text">21 | fn returns_errors(input: u8) -> Result<String, Error> {
|
|
| ^^^^^^^^^^^^^^^^^^^^^ doesn't have a size known at compile-time
|
|
</code></pre>
|
|
<p>This is not surprising, because we know that a trait can work on many things, and they each have different sizes.</p>
|
|
|
|
</main>
|
|
|
|
<nav class="nav-wrapper" aria-label="Page navigation">
|
|
<!-- Mobile navigation buttons -->
|
|
|
|
<a rel="prev" href="Chapter_53.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" href="Chapter_55.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="Chapter_53.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" href="Chapter_55.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.playground_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 -->
|
|
|
|
|
|
|
|
|
|
</body>
|
|
</html>
|