<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/runner/.cargo/registry/src/index.crates.io-6f17d22bba15001f/quote-1.0.38/src/format.rs`."><title>format.rs - source</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../../static.files/rustdoc-42caa33d.css"><meta name="rustdoc-vars" data-root-path="../../" data-static-root-path="../../static.files/" data-current-crate="quote" data-themes="" data-resource-suffix="" data-rustdoc-version="1.84.0 (9fc6b4312 2025-01-07)" data-channel="1.84.0" data-search-js="search-92e6798f.js" data-settings-js="settings-0f613d39.js" ><script src="../../static.files/storage-59e33391.js"></script><script defer src="../../static.files/src-script-56102188.js"></script><script defer src="../../src-files.js"></script><script defer src="../../static.files/main-5f194d8c.js"></script><noscript><link rel="stylesheet" href="../../static.files/noscript-893ab5e7.css"></noscript><link rel="alternate icon" type="image/png" href="../../static.files/favicon-32x32-6580c154.png"><link rel="icon" type="image/svg+xml" href="../../static.files/favicon-044be391.svg"></head><body class="rustdoc src"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="src-sidebar-title"><h2>Files</h2></div></nav><div class="sidebar-resizer"></div><main><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><h1><div class="sub-heading">quote/</div>format.rs</h1><rustdoc-toolbar></rustdoc-toolbar></div><div class="example-wrap"><div data-nosnippet><pre class="src-line-numbers"> <a href="#1" id="1">1</a> <a href="#2" id="2">2</a> <a href="#3" id="3">3</a> <a href="#4" id="4">4</a> <a href="#5" id="5">5</a> <a href="#6" id="6">6</a> <a href="#7" id="7">7</a> <a href="#8" id="8">8</a> <a href="#9" id="9">9</a> <a href="#10" id="10">10</a> <a href="#11" id="11">11</a> <a href="#12" id="12">12</a> <a href="#13" id="13">13</a> <a href="#14" id="14">14</a> <a href="#15" id="15">15</a> <a href="#16" id="16">16</a> <a href="#17" id="17">17</a> <a href="#18" id="18">18</a> <a href="#19" id="19">19</a> <a href="#20" id="20">20</a> <a href="#21" id="21">21</a> <a href="#22" id="22">22</a> <a href="#23" id="23">23</a> <a href="#24" id="24">24</a> <a href="#25" id="25">25</a> <a href="#26" id="26">26</a> <a href="#27" id="27">27</a> <a href="#28" id="28">28</a> <a href="#29" id="29">29</a> <a href="#30" id="30">30</a> <a href="#31" id="31">31</a> <a href="#32" id="32">32</a> <a href="#33" id="33">33</a> <a href="#34" id="34">34</a> <a href="#35" id="35">35</a> <a href="#36" id="36">36</a> <a href="#37" id="37">37</a> <a href="#38" id="38">38</a> <a href="#39" id="39">39</a> <a href="#40" id="40">40</a> <a href="#41" id="41">41</a> <a href="#42" id="42">42</a> <a href="#43" id="43">43</a> <a href="#44" id="44">44</a> <a href="#45" id="45">45</a> <a href="#46" id="46">46</a> <a href="#47" id="47">47</a> <a href="#48" id="48">48</a> <a href="#49" id="49">49</a> <a href="#50" id="50">50</a> <a href="#51" id="51">51</a> <a href="#52" id="52">52</a> <a href="#53" id="53">53</a> <a href="#54" id="54">54</a> <a href="#55" id="55">55</a> <a href="#56" id="56">56</a> <a href="#57" id="57">57</a> <a href="#58" id="58">58</a> <a href="#59" id="59">59</a> <a href="#60" id="60">60</a> <a href="#61" id="61">61</a> <a href="#62" id="62">62</a> <a href="#63" id="63">63</a> <a href="#64" id="64">64</a> <a href="#65" id="65">65</a> <a href="#66" id="66">66</a> <a href="#67" id="67">67</a> <a href="#68" id="68">68</a> <a href="#69" id="69">69</a> <a href="#70" id="70">70</a> <a href="#71" id="71">71</a> <a href="#72" id="72">72</a> <a href="#73" id="73">73</a> <a href="#74" id="74">74</a> <a href="#75" id="75">75</a> <a href="#76" id="76">76</a> <a href="#77" id="77">77</a> <a href="#78" id="78">78</a> <a href="#79" id="79">79</a> <a href="#80" id="80">80</a> <a href="#81" id="81">81</a> <a href="#82" id="82">82</a> <a href="#83" id="83">83</a> <a href="#84" id="84">84</a> <a href="#85" id="85">85</a> <a href="#86" id="86">86</a> <a href="#87" id="87">87</a> <a href="#88" id="88">88</a> <a href="#89" id="89">89</a> <a href="#90" id="90">90</a> <a href="#91" id="91">91</a> <a href="#92" id="92">92</a> <a href="#93" id="93">93</a> <a href="#94" id="94">94</a> <a href="#95" id="95">95</a> <a href="#96" id="96">96</a> <a href="#97" id="97">97</a> <a href="#98" id="98">98</a> <a href="#99" id="99">99</a> <a href="#100" id="100">100</a> <a href="#101" id="101">101</a> <a href="#102" id="102">102</a> <a href="#103" id="103">103</a> <a href="#104" id="104">104</a> <a href="#105" id="105">105</a> <a href="#106" id="106">106</a> <a href="#107" id="107">107</a> <a href="#108" id="108">108</a> <a href="#109" id="109">109</a> <a href="#110" id="110">110</a> <a href="#111" id="111">111</a> <a href="#112" id="112">112</a> <a href="#113" id="113">113</a> <a href="#114" id="114">114</a> <a href="#115" id="115">115</a> <a href="#116" id="116">116</a> <a href="#117" id="117">117</a> <a href="#118" id="118">118</a> <a href="#119" id="119">119</a> <a href="#120" id="120">120</a> <a href="#121" id="121">121</a> <a href="#122" id="122">122</a> <a href="#123" id="123">123</a> <a href="#124" id="124">124</a> <a href="#125" id="125">125</a> <a href="#126" id="126">126</a> <a href="#127" id="127">127</a> <a href="#128" id="128">128</a> <a href="#129" id="129">129</a> <a href="#130" id="130">130</a> <a href="#131" id="131">131</a> <a href="#132" id="132">132</a> <a href="#133" id="133">133</a> <a href="#134" id="134">134</a> <a href="#135" id="135">135</a> <a href="#136" id="136">136</a> <a href="#137" id="137">137</a> <a href="#138" id="138">138</a> <a href="#139" id="139">139</a> <a href="#140" id="140">140</a> <a href="#141" id="141">141</a> <a href="#142" id="142">142</a> <a href="#143" id="143">143</a> <a href="#144" id="144">144</a> <a href="#145" id="145">145</a> <a href="#146" id="146">146</a> <a href="#147" id="147">147</a> <a href="#148" id="148">148</a> <a href="#149" id="149">149</a> <a href="#150" id="150">150</a> <a href="#151" id="151">151</a> <a href="#152" id="152">152</a> <a href="#153" id="153">153</a> <a href="#154" id="154">154</a> <a href="#155" id="155">155</a> <a href="#156" id="156">156</a> <a href="#157" id="157">157</a> <a href="#158" id="158">158</a> <a href="#159" id="159">159</a> <a href="#160" id="160">160</a> <a href="#161" id="161">161</a> <a href="#162" id="162">162</a> <a href="#163" id="163">163</a> <a href="#164" id="164">164</a> <a href="#165" id="165">165</a> <a href="#166" id="166">166</a> <a href="#167" id="167">167</a> <a href="#168" id="168">168</a></pre></div><pre class="rust"><code><span class="doccomment">/// Formatting macro for constructing `Ident`s. /// /// <br> /// /// # Syntax /// /// Syntax is copied from the [`format!`] macro, supporting both positional and /// named arguments. /// /// Only a limited set of formatting traits are supported. The current mapping /// of format types to traits is: /// /// * `{}` ⇒ [`IdentFragment`] /// * `{:o}` ⇒ [`Octal`](std::fmt::Octal) /// * `{:x}` ⇒ [`LowerHex`](std::fmt::LowerHex) /// * `{:X}` ⇒ [`UpperHex`](std::fmt::UpperHex) /// * `{:b}` ⇒ [`Binary`](std::fmt::Binary) /// /// See [`std::fmt`] for more information. /// /// <br> /// /// # IdentFragment /// /// Unlike `format!`, this macro uses the [`IdentFragment`] formatting trait by /// default. This trait is like `Display`, with a few differences: /// /// * `IdentFragment` is only implemented for a limited set of types, such as /// unsigned integers and strings. /// * [`Ident`] arguments will have their `r#` prefixes stripped, if present. /// /// [`IdentFragment`]: crate::IdentFragment /// [`Ident`]: proc_macro2::Ident /// /// <br> /// /// # Hygiene /// /// The [`Span`] of the first `Ident` argument is used as the span of the final /// identifier, falling back to [`Span::call_site`] when no identifiers are /// provided. /// /// ``` /// # use quote::format_ident; /// # let ident = format_ident!("Ident"); /// // If `ident` is an Ident, the span of `my_ident` will be inherited from it. /// let my_ident = format_ident!("My{}{}", ident, "IsCool"); /// assert_eq!(my_ident, "MyIdentIsCool"); /// ``` /// /// Alternatively, the span can be overridden by passing the `span` named /// argument. /// /// ``` /// # use quote::format_ident; /// # const IGNORE_TOKENS: &'static str = stringify! { /// let my_span = /* ... */; /// # }; /// # let my_span = proc_macro2::Span::call_site(); /// format_ident!("MyIdent", span = my_span); /// ``` /// /// [`Span`]: proc_macro2::Span /// [`Span::call_site`]: proc_macro2::Span::call_site /// /// <p><br></p> /// /// # Panics /// /// This method will panic if the resulting formatted string is not a valid /// identifier. /// /// <br> /// /// # Examples /// /// Composing raw and non-raw identifiers: /// ``` /// # use quote::format_ident; /// let my_ident = format_ident!("My{}", "Ident"); /// assert_eq!(my_ident, "MyIdent"); /// /// let raw = format_ident!("r#Raw"); /// assert_eq!(raw, "r#Raw"); /// /// let my_ident_raw = format_ident!("{}Is{}", my_ident, raw); /// assert_eq!(my_ident_raw, "MyIdentIsRaw"); /// ``` /// /// Integer formatting options: /// ``` /// # use quote::format_ident; /// let num: u32 = 10; /// /// let decimal = format_ident!("Id_{}", num); /// assert_eq!(decimal, "Id_10"); /// /// let octal = format_ident!("Id_{:o}", num); /// assert_eq!(octal, "Id_12"); /// /// let binary = format_ident!("Id_{:b}", num); /// assert_eq!(binary, "Id_1010"); /// /// let lower_hex = format_ident!("Id_{:x}", num); /// assert_eq!(lower_hex, "Id_a"); /// /// let upper_hex = format_ident!("Id_{:X}", num); /// assert_eq!(upper_hex, "Id_A"); /// ``` </span><span class="attr">#[macro_export] </span><span class="macro">macro_rules!</span> format_ident { (<span class="macro-nonterminal">$fmt</span>:expr) => { <span class="macro-nonterminal">$</span><span class="macro">crate::format_ident_impl!</span>([ <span class="macro-nonterminal">$crate::__private::Option::None</span>, <span class="macro-nonterminal">$fmt </span>]) }; (<span class="macro-nonterminal">$fmt</span>:expr, $(<span class="macro-nonterminal">$rest</span>:tt)<span class="kw-2">*</span>) => { <span class="macro-nonterminal">$</span><span class="macro">crate::format_ident_impl!</span>([ <span class="macro-nonterminal">$crate::__private::Option::None</span>, <span class="macro-nonterminal">$fmt </span>] $(<span class="macro-nonterminal">$rest</span>)<span class="kw-2">*</span>) }; } <span class="attr">#[macro_export] #[doc(hidden)] </span><span class="macro">macro_rules!</span> format_ident_impl { <span class="comment">// Final state </span>([<span class="macro-nonterminal">$span</span>:expr, $(<span class="macro-nonterminal">$fmt</span>:tt)<span class="kw-2">*</span>]) => { <span class="macro-nonterminal">$crate::__private::mk_ident</span>( <span class="kw-2">&</span><span class="macro-nonterminal">$</span><span class="macro">crate::__private::format!</span>($(<span class="macro-nonterminal">$fmt</span>)<span class="kw-2">*</span>), <span class="macro-nonterminal">$span</span>, ) }; <span class="comment">// Span argument </span>([<span class="macro-nonterminal">$old</span>:expr, $(<span class="macro-nonterminal">$fmt</span>:tt)<span class="kw-2">*</span>] span = <span class="macro-nonterminal">$span</span>:expr) => { <span class="macro-nonterminal">$</span><span class="macro">crate::format_ident_impl!</span>([<span class="macro-nonterminal">$old</span>, $(<span class="macro-nonterminal">$fmt</span>)<span class="kw-2">*</span>] span = <span class="macro-nonterminal">$span</span>,) }; ([<span class="macro-nonterminal">$old</span>:expr, $(<span class="macro-nonterminal">$fmt</span>:tt)<span class="kw-2">*</span>] span = <span class="macro-nonterminal">$span</span>:expr, $(<span class="macro-nonterminal">$rest</span>:tt)<span class="kw-2">*</span>) => { <span class="macro-nonterminal">$</span><span class="macro">crate::format_ident_impl!</span>([ <span class="macro-nonterminal">$crate::__private::Option::Some</span>::<<span class="macro-nonterminal">$crate::__private::Span</span>>(<span class="macro-nonterminal">$span</span>), $(<span class="macro-nonterminal">$fmt</span>)* ] $(<span class="macro-nonterminal">$rest</span>)<span class="kw-2">*</span>) }; <span class="comment">// Named argument </span>([<span class="macro-nonterminal">$span</span>:expr, $(<span class="macro-nonterminal">$fmt</span>:tt)<span class="kw-2">*</span>] <span class="macro-nonterminal">$name</span>:ident = <span class="macro-nonterminal">$arg</span>:expr) => { <span class="macro-nonterminal">$</span><span class="macro">crate::format_ident_impl!</span>([<span class="macro-nonterminal">$span</span>, $(<span class="macro-nonterminal">$fmt</span>)<span class="kw-2">*</span>] <span class="macro-nonterminal">$name </span>= <span class="macro-nonterminal">$arg</span>,) }; ([<span class="macro-nonterminal">$span</span>:expr, $(<span class="macro-nonterminal">$fmt</span>:tt)<span class="kw-2">*</span>] <span class="macro-nonterminal">$name</span>:ident = <span class="macro-nonterminal">$arg</span>:expr, $(<span class="macro-nonterminal">$rest</span>:tt)<span class="kw-2">*</span>) => { <span class="kw">match </span><span class="macro-nonterminal">$crate::__private::IdentFragmentAdapter</span>(<span class="kw-2">&</span><span class="macro-nonterminal">$arg</span>) { arg => <span class="macro-nonterminal">$</span><span class="macro">crate::format_ident_impl!</span>([<span class="macro-nonterminal">$span</span>.or(arg.span()), $(<span class="macro-nonterminal">$fmt</span>)<span class="kw-2">*</span>, <span class="macro-nonterminal">$name </span>= arg] $(<span class="macro-nonterminal">$rest</span>)<span class="kw-2">*</span>), } }; <span class="comment">// Positional argument </span>([<span class="macro-nonterminal">$span</span>:expr, $(<span class="macro-nonterminal">$fmt</span>:tt)<span class="kw-2">*</span>] <span class="macro-nonterminal">$arg</span>:expr) => { <span class="macro-nonterminal">$</span><span class="macro">crate::format_ident_impl!</span>([<span class="macro-nonterminal">$span</span>, $(<span class="macro-nonterminal">$fmt</span>)<span class="kw-2">*</span>] <span class="macro-nonterminal">$arg</span>,) }; ([<span class="macro-nonterminal">$span</span>:expr, $(<span class="macro-nonterminal">$fmt</span>:tt)<span class="kw-2">*</span>] <span class="macro-nonterminal">$arg</span>:expr, $(<span class="macro-nonterminal">$rest</span>:tt)<span class="kw-2">*</span>) => { <span class="kw">match </span><span class="macro-nonterminal">$crate::__private::IdentFragmentAdapter</span>(<span class="kw-2">&</span><span class="macro-nonterminal">$arg</span>) { arg => <span class="macro-nonterminal">$</span><span class="macro">crate::format_ident_impl!</span>([<span class="macro-nonterminal">$span</span>.or(arg.span()), $(<span class="macro-nonterminal">$fmt</span>)<span class="kw-2">*</span>, arg] $(<span class="macro-nonterminal">$rest</span>)<span class="kw-2">*</span>), } }; } </code></pre></div></section></main></body></html>