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  19. </a></div> <!----></nav>  <ul class="sidebar-links"><li><section class="sidebar-group depth-0"><p class="sidebar-heading open"><span>Rust 入门教程（三）</span> <!----></p> <ul class="sidebar-links sidebar-group-items"><li><a href="/rust_camp_tutorial/Rust%E6%96%87%E6%A1%A3/Rust%E5%85%A5%E9%97%A8%E6%95%99%E7%A8%8B%EF%BC%88%E4%B8%89%EF%BC%89.html#_1-package-和-crate" class="sidebar-link">1. Package 和 Crate</a><ul class="sidebar-sub-headers"></ul></li><li><a href="/rust_camp_tutorial/Rust%E6%96%87%E6%A1%A3/Rust%E5%85%A5%E9%97%A8%E6%95%99%E7%A8%8B%EF%BC%88%E4%B8%89%EF%BC%89.html#_2-路径-path" class="sidebar-link">2. 路径(Path)</a><ul class="sidebar-sub-headers"></ul></li><li><a href="/rust_camp_tutorial/Rust%E6%96%87%E6%A1%A3/Rust%E5%85%A5%E9%97%A8%E6%95%99%E7%A8%8B%EF%BC%88%E4%B8%89%EF%BC%89.html#_3-use-关键字" class="sidebar-link">3. use 关键字</a><ul class="sidebar-sub-headers"></ul></li><li><a href="/rust_camp_tutorial/Rust%E6%96%87%E6%A1%A3/Rust%E5%85%A5%E9%97%A8%E6%95%99%E7%A8%8B%EF%BC%88%E4%B8%89%EF%BC%89.html#_4-将模块拆分为不同文件" class="sidebar-link">4. 将模块拆分为不同文件</a><ul class="sidebar-sub-headers"></ul></li></ul></section></li></ul> </aside> <main class="page"> <div class="theme-default-content content__default"><h1 id="rust-入门教程-三"><a href="#rust-入门教程-三" class="header-anchor">#</a> Rust 入门教程（三）</h1> <p><strong>Rust 的代码组织</strong></p> <p>代码组织主要包括：</p> <ul><li>哪些细节可以暴露，哪些细节是私有的一作用域内哪些名称有效</li> <li>模块系统:
    20. 

  20. <ul><li>Package（包）：Cargo 的特性，让你构建、测试、共享 crate</li> <li>Crate（单元包）： 一个模块树，它可产生一个 library 或可执行文件</li> <li>Module（模块）、use：让你控制代码的组织、作用域、私有路径</li> <li>Path（路径）：为 struct、function 或 module 等项命名的方式</li></ul></li></ul> <h2 id="_1-package-和-crate"><a href="#_1-package-和-crate" class="header-anchor">#</a> 1. Package 和 Crate</h2> <p>Crate的类型:</p> <ul><li>binary</li> <li>library</li></ul> <p>Crate Root:</p> <ul><li>是源代码文件</li> <li>Rust编译器从这里开始，组成你的 Crate 的根Module</li></ul> <p>一个 Package:</p> <ul><li>包含 1 个 Cargo.toml，它描述了如何构建这些 Crates</li> <li>只能包含 0-1 个 library crate</li> <li>可以包含任意数量的 binary crate</li> <li>但必须至少包含一个 crate (library 或 binary)</li></ul> <p><strong>Cargo 的惯例</strong></p> <p><code>src/main.rs</code>:</p> <ul><li>binary crate 的 crate root</li> <li>crate 名与 package 名相同</li></ul> <p><code>src/lib.rs</code>:</p> <ul><li>package 包含一个 library crate</li> <li>library crate 的 crate root</li> <li>crate 名与 package 名相同</li></ul> <p>Cargo 把 crate root 文件交给 rustc 来构建 library 或 binary</p> <p>如果 package 下有一个lib.rs，就说明 package 下面有一个 library crate，这个 lib.rs 就是这个 library crate 的入口文件，crate 名字也是叫 my-project.</p> <p>一个 Package 可以同时包含 src/main.r s和 src/lib.rs</p> <ul><li>一个 binary crate，一个 library crate</li> <li>名称与 package 名相同</li></ul> <p>一个 Package 可以有多个 binary crate:</p> <ul><li>文件放在 src/bin</li> <li>每个文件是单独的 binary crate</li></ul> <p><strong>Crate 的作用</strong></p> <p>将相关功能组合到一个作用域内，便于在项目间进行共享，防止冲突。例如 rand crate，访问它的功能需要通过它的名字:rand</p> <p><strong>定义 module 来控制作用域和私有性</strong></p> <p>Module:</p> <ul><li>在一个crate内，将代码进行分组</li> <li>增加可读性，易于复用</li> <li>控制项目（item）的私有性。public、private</li></ul> <p>建立 module:</p> <ul><li>mod 关键字</li> <li>可嵌套</li> <li>可包含其它项（struct、enum、常量、trait、函数等）的定义</li></ul> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">mod</span> <span class="token module-declaration namespace">front_of_house</span> <span class="token punctuation">{</span>
    21. 

  21.     <span class="token keyword">mod</span> <span class="token module-declaration namespace">hosting</span> <span class="token punctuation">{</span>
    22. 

  22.         <span class="token keyword">fn</span> <span class="token function-definition function">add_to_waitlist</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span><span class="token punctuation">}</span>
    23. 

  23.         <span class="token keyword">fn</span> <span class="token function-definition function">seat_at_table</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span><span class="token punctuation">}</span>
    24. 

  24.     <span class="token punctuation">}</span>
    25. 

  25.     
    26. 

  26.     <span class="token keyword">mod</span> <span class="token module-declaration namespace">serving</span> <span class="token punctuation">{</span>
    27. 

  27.         <span class="token keyword">fn</span> <span class="token function-definition function">take_order</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span><span class="token punctuation">}</span>
    28. 

  28.         <span class="token keyword">fn</span> <span class="token function-definition function">serve_order</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span><span class="token punctuation">}</span>
    29. 

  29.         <span class="token keyword">fn</span> <span class="token function-definition function">take_payment</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span><span class="token punctuation">}</span>
    30. 

  30.     <span class="token punctuation">}</span>
    31. 

  31. <span class="token punctuation">}</span>
    32. 

  32. </code></pre></div><p><img src="https://raw.githubusercontent.com/CherryYang05/PicGo-image/master/images/20220514204827.png" alt="crate树形结构"></p> <p><code>src/main.rs</code> 和 <code>src/lib.rs</code> 叫做 <code>crate roots</code>:</p> <ul><li>这两个文件（任意一个）的内容形成了名为 crate 的模块，位于整个模块树的根部</li> <li>整个模块树在隐式的crate模块下</li></ul> <h2 id="_2-路径-path"><a href="#_2-路径-path" class="header-anchor">#</a> 2. 路径(Path)</h2> <p>为了在 Rust 的模块中找到某个条目，需要使用路径。路径的两种形式:</p> <ul><li>绝对路径:从 crate root开始，使用 crate 名或字面值 crate</li> <li>相对路径:从当前模块开始，使用 self，super 或当前模块的标识符路径至少由一个标识符组成，标识符之间使用<code>::</code></li></ul> <p><strong>私有边界（privacy boundary）</strong></p> <ul><li>模块不仅可以组织代码，还可以定义私有边界</li> <li>如果想把函数或结构体设为私有，可以将它放到某个模块中</li> <li>Rust中所有的条目（函数，方法，struct，enum，模块，常量）默认是私有的</li> <li>父级模块无法访问子模块中的私有条目</li> <li>子模块里可以使用所有祖先模块中的条目</li></ul> <p><strong>Pub 关键字</strong></p> <p>使用 <code>pub</code> 关键字将某些条目标记为公共的，同为根下的模块尽管都是私有，也可以访问</p> <p><strong>super 关键字</strong></p> <p>用来访问父级模块路径中的内容，类似文件系统中的 <code>..</code>，例子如下：</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">mod</span> <span class="token module-declaration namespace">back_of_house</span> <span class="token punctuation">{</span>
    33. 

  33.     <span class="token keyword">fn</span> <span class="token function-definition function">fix_incorrect_order</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    34. 

  34.         <span class="token function">cook_order</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    35. 

  35.         <span class="token keyword">super</span><span class="token module-declaration namespace"><span class="token punctuation">::</span>serve_order</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    36. 

  36.         <span class="token keyword">crate</span><span class="token module-declaration namespace"><span class="token punctuation">::</span>serve_order</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    37. 

  37.     <span class="token punctuation">}</span>
    38. 

  38. 

  39.     <span class="token keyword">fn</span> <span class="token function-definition function">cook_order</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span><span class="token punctuation">}</span>
    40. 

  40. <span class="token punctuation">}</span>
    41. 

  41. <span class="token keyword">fn</span> <span class="token function-definition function">serve_order</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span><span class="token punctuation">}</span>
    42. 

  42. </code></pre></div><p><strong>pub struct</strong></p> <p>pub 放在 struct 前:</p> <ul><li>struct 是公共的</li> <li>struct 的字段默认是私有的</li> <li>struct 的字段需要<strong>单独设置</strong> pub 来变成公有</li></ul> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">mod</span> <span class="token module-declaration namespace">back_of_house</span> <span class="token punctuation">{</span>
    43. 

  43.     <span class="token keyword">pub</span> <span class="token keyword">struct</span> <span class="token type-definition class-name">Breakfast</span> <span class="token punctuation">{</span>
    44. 

  44.         <span class="token keyword">pub</span> toast<span class="token punctuation">:</span> <span class="token class-name">String</span><span class="token punctuation">,</span>
    45. 

  45.         fruit<span class="token punctuation">:</span> <span class="token class-name">String</span><span class="token punctuation">,</span>
    46. 

  46.     <span class="token punctuation">}</span>
    47. 

  47. 

  48.     <span class="token keyword">impl</span> <span class="token class-name">Breakfast</span> <span class="token punctuation">{</span>
    49. 

  49.         <span class="token keyword">pub</span> <span class="token keyword">fn</span> <span class="token function-definition function">summer</span><span class="token punctuation">(</span>toast<span class="token punctuation">:</span> <span class="token operator">&amp;</span><span class="token keyword">str</span><span class="token punctuation">)</span> <span class="token punctuation">-&gt;</span> <span class="token class-name">Breakfast</span> <span class="token punctuation">{</span>
    50. 

  50.             <span class="token class-name">Breakfast</span> <span class="token punctuation">{</span>
    51. 

  51.                 toast<span class="token punctuation">:</span> <span class="token class-name">String</span><span class="token punctuation">::</span><span class="token function">from</span><span class="token punctuation">(</span>toast<span class="token punctuation">)</span><span class="token punctuation">,</span>
    52. 

  52.                 fruit<span class="token punctuation">:</span> <span class="token class-name">String</span><span class="token punctuation">::</span><span class="token function">from</span><span class="token punctuation">(</span><span class="token string">&quot;strawberry&quot;</span><span class="token punctuation">)</span><span class="token punctuation">,</span>
    53. 

  53.             <span class="token punctuation">}</span>
    54. 

  54.         <span class="token punctuation">}</span>
    55. 

  55.     <span class="token punctuation">}</span>
    56. 

  56. <span class="token punctuation">}</span>
    57. 

  57. 

  58. <span class="token keyword">pub</span> <span class="token keyword">fn</span> <span class="token function-definition function">eat_at_restaurant</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    59. 

  59.     <span class="token keyword">let</span> <span class="token keyword">mut</span> meal <span class="token operator">=</span> <span class="token namespace">back_of_house<span class="token punctuation">::</span></span><span class="token class-name">Breakfast</span><span class="token punctuation">::</span><span class="token function">summer</span><span class="token punctuation">(</span><span class="token string">&quot;Rye&quot;</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    60. 

  60.     <span class="token macro property">println!</span><span class="token punctuation">(</span><span class="token string">&quot;I'd like {} toast please.&quot;</span><span class="token punctuation">,</span> meal<span class="token punctuation">.</span>toast<span class="token punctuation">)</span><span class="token punctuation">;</span>
    61. 

  61. <span class="token punctuation">}</span>
    62. 

  62. </code></pre></div><p><strong>pub enum</strong></p> <p>pub 放在 enum 前:</p> <ul><li>enum 是公共的</li> <li><strong>enum 的变体也都是公共的</strong></li></ul> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">mod</span> <span class="token module-declaration namespace">back_of_house</span> <span class="token punctuation">{</span>
    63. 

  63.     <span class="token keyword">pub</span> <span class="token keyword">enum</span> <span class="token type-definition class-name">Appetizer</span> <span class="token punctuation">{</span>
    64. 

  64.         <span class="token class-name">Soup</span><span class="token punctuation">,</span>
    65. 

  65.         <span class="token class-name">Salad</span>
    66. 

  66.     <span class="token punctuation">}</span>
    67. 

  67. <span class="token punctuation">}</span>
    68. 

  68. </code></pre></div><h2 id="_3-use-关键字"><a href="#_3-use-关键字" class="header-anchor">#</a> 3. use 关键字</h2> <p>可以使用 <code>use</code> 将路径导入到作用域内，同样遵循私有性原则，即只有公共的才能被使用</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">mod</span> <span class="token module-declaration namespace">front_of_house</span> <span class="token punctuation">{</span>
    69. 

  69.     <span class="token keyword">pub</span> <span class="token keyword">mod</span> <span class="token module-declaration namespace">hosting</span> <span class="token punctuation">{</span>
    70. 

  70.         <span class="token keyword">pub</span> <span class="token keyword">fn</span> <span class="token function-definition function">add_to_waitlist</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span><span class="token punctuation">}</span>
    71. 

  71.         <span class="token keyword">fn</span> <span class="token function-definition function">some_function</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span><span class="token punctuation">}</span>
    72. 

  72.     <span class="token punctuation">}</span>
    73. 

  73. <span class="token punctuation">}</span>
    74. 

  74. 

  75. <span class="token keyword">use</span> <span class="token keyword">crate</span><span class="token module-declaration namespace"><span class="token punctuation">::</span>front_of_house<span class="token punctuation">::</span></span>hosting<span class="token punctuation">;</span>
    76. 

  76. 

  77. <span class="token keyword">pub</span> <span class="token keyword">fn</span> <span class="token function-definition function">eat_at_restaurant</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
    78. 

  78.     <span class="token namespace">hosting<span class="token punctuation">::</span></span><span class="token function">add_to_waitlist</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    79. 

  79.     <span class="token namespace">hosting<span class="token punctuation">::</span></span><span class="token function">add_to_waitlist</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    80. 

  80.     <span class="token namespace">hosting<span class="token punctuation">::</span></span><span class="token function">add_to_waitlist</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    81. 

  81.     <span class="token namespace">hosting<span class="token punctuation">::</span></span><span class="token function">some_function</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>   <span class="token comment">//报错，因为some_function为私有</span>
    82. 

  82. <span class="token punctuation">}</span>
    83. 

  83. </code></pre></div><p>使用 <code>use</code> 指定相对路径：<code>use front_of_house::hosting;</code></p> <p>可以直接将模块中的函数导入到作用域内，但是这样便无法区分该函数是在模块中定义还是在该文件内定义，因此通常的做法都是只导入到该函数的父模块，通过父模块调用函数。</p> <p>对于函数和同名条目是这样，但是对于结构体和枚举，通常是指定完整路径，这是 <code>use</code> 的习惯用法。</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">use</span> <span class="token namespace">std<span class="token punctuation">::</span></span>fmt<span class="token punctuation">;</span>
    84. 

  84. <span class="token keyword">use</span> <span class="token namespace">std<span class="token punctuation">::</span></span>io<span class="token punctuation">;</span>
    85. 

  85. 

  86. <span class="token keyword">fn</span> <span class="token function-definition function">f1</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">-&gt;</span> <span class="token namespace">fmt<span class="token punctuation">::</span></span><span class="token class-name">Result</span> <span class="token punctuation">{</span><span class="token punctuation">}</span>
    87. 

  87. 

  88. <span class="token keyword">fn</span> <span class="token function-definition function">f2</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">-&gt;</span> <span class="token namespace">io<span class="token punctuation">::</span></span><span class="token class-name">Result</span> <span class="token punctuation">{</span><span class="token punctuation">}</span>
    89. 

  89. </code></pre></div><p><strong>as 关键字</strong></p> <p><code>as</code> 关键字可以为引入的路径指定一个本地的别名，例子如下：</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">use</span> <span class="token namespace">std<span class="token punctuation">::</span>fmt<span class="token punctuation">::</span></span><span class="token class-name">Result</span><span class="token punctuation">;</span>
    90. 

  90. <span class="token keyword">use</span> <span class="token namespace">std<span class="token punctuation">::</span>io<span class="token punctuation">::</span></span><span class="token class-name">IOResult</span><span class="token punctuation">;</span>
    91. 

  91. 

  92. <span class="token keyword">fn</span> <span class="token function-definition function">f1</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">-&gt;</span> <span class="token class-name">Result</span> <span class="token punctuation">{</span><span class="token punctuation">}</span>
    93. 

  93. <span class="token keyword">fn</span> <span class="token function-definition function">f2</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">-&gt;</span> <span class="token class-name">IOResult</span> <span class="token punctuation">{</span><span class="token punctuation">}</span>
    94. 

  94. </code></pre></div><p><strong>使用 pub use 重新导出名称</strong></p> <p>使用 use 将路径（名称）导入到作用域内后，该名称在此作用域内是私有的</p> <p>pub use:重导出</p> <ul><li>将条目引入作用域</li> <li>该条目可以被外部代码引入到它们的作用域</li></ul> <p><code>pub use crate::front_of_house::hosting;</code></p> <p><strong>使用外部包</strong></p> <ol><li>Cargo.toml 添加依赖的包(package)
    95. 

  95. <ul><li>https://crates.io/</li></ul></li> <li>use 将特定条目引入作用域</li></ol> <p>标准库（std）也被当做外部包，但是不需要修改 Cargo.toml 来包含 std，需要使用 use 将 std 中的特定条目引入当前作用域</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">use</span> <span class="token namespace">std<span class="token punctuation">::</span>collections<span class="token punctuation">::</span></span><span class="token class-name">HashMap</span><span class="token punctuation">;</span>
    96. 

  96. </code></pre></div><p><strong>使用嵌套路径清理大量 use 语句</strong></p> <p>如果使用同一个包或模块下的多个条目，可以使用嵌套路径在同一行内将上述路径进行引入</p> <p>格式如下：<code>路径相同的部分::{路径不同的部分}</code>，例子如下：</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">use</span> <span class="token namespace">std<span class="token punctuation">::</span>cmp<span class="token punctuation">::</span></span><span class="token class-name">Ordering</span><span class="token punctuation">;</span>
    97. 

  97. <span class="token keyword">use</span> <span class="token namespace">std<span class="token punctuation">::</span></span>io<span class="token punctuation">;</span>
    98. 

  98. 

  99. <span class="token comment">//使用嵌套路径</span>
    100. 

  100. <span class="token keyword">use</span> <span class="token namespace">std<span class="token punctuation">::</span></span><span class="token punctuation">{</span><span class="token namespace">cmp<span class="token punctuation">::</span></span><span class="token class-name">Ordering</span><span class="token punctuation">,</span> io<span class="token punctuation">}</span><span class="token punctuation">;</span>
    101. 

  101. 

  102. <span class="token comment">//若是这样的引用</span>
    103. 

  103. <span class="token keyword">use</span> <span class="token namespace">std<span class="token punctuation">::</span></span>io<span class="token punctuation">;</span>
    104. 

  104. <span class="token keyword">use</span> <span class="token namespace">std<span class="token punctuation">::</span>io<span class="token punctuation">::</span></span><span class="token class-name">Write</span><span class="token punctuation">;</span>
    105. 

  105. 

  106. <span class="token comment">//简写为</span>
    107. 

  107. <span class="token keyword">use</span> <span class="token namespace">std<span class="token punctuation">::</span>io<span class="token punctuation">::</span></span><span class="token punctuation">{</span><span class="token keyword">self</span><span class="token punctuation">,</span> <span class="token class-name">Write</span><span class="token punctuation">}</span><span class="token punctuation">;</span>
    108. 

  108. </code></pre></div><p><strong>通配符*</strong></p> <p>使用 <code>*</code> 可以把路径中所有的公共条目都引入到作用域</p> <p><code>use std::collections::*;</code></p> <p>应用场景:</p> <ul><li>测试。将所有被测试代码引入到 tests 模块</li> <li>有时被用于预导入（prelude）模块</li></ul> <h2 id="_4-将模块拆分为不同文件"><a href="#_4-将模块拆分为不同文件" class="header-anchor">#</a> 4. 将模块拆分为不同文件</h2> <p><strong>将模块内容移动到其它文件</strong></p> <p>模块定义时，如果模块名后边是 <code>;</code>，而不是代码块，Rust 会从与模块同名的文件中加载内容，同时项目文件夹结构要与模块层级结构一致。随着模块的变大，该技术可以把模块中的内容移动到其他文件中。</p> <p>例如：文件 <code>main.rs</code>:</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">pub</span> <span class="token keyword">mod</span> <span class="token module-declaration namespace">back_of_house</span><span class="token punctuation">;</span>
    109. 

  109. </code></pre></div><p>文件 <code>back_of_house.rs</code>:</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">pub</span> <span class="token keyword">mod</span> <span class="token module-declaration namespace">hosting</span><span class="token punctuation">;</span>
    110. 

  110. </code></pre></div><p>这时必须在 <code>src</code> 下创建一个 <code>back_of_house</code> 的文件夹，里面创建一个 <code>hosting.rs</code> 文件，即为 <code>src/back_of_house/hosting.rs</code></p> <p>文件 <code>hosting.rs</code>:</p> <div class="language-rust extra-class"><pre class="language-rust"><code><span class="token keyword">pub</span> <span class="token keyword">fn</span> <span class="token function-definition function">test</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span><span class="token punctuation">}</span>
    111. 

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