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<!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="An attribute, like `#[repr(transparent)]`."><title>Attribute in syn - Rust</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/SourceSerif4-Regular-46f98efaafac5295.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/FiraSans-Regular-018c141bf0843ffd.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/FiraSans-Medium-8f9a781e4970d388.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2"><link rel="stylesheet" href="../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../static.files/rustdoc-ac92e1bbe349e143.css"><meta name="rustdoc-vars" data-root-path="../" data-static-root-path="../static.files/" data-current-crate="syn" data-themes="" data-resource-suffix="" data-rustdoc-version="1.76.0 (07dca489a 2024-02-04)" data-channel="1.76.0" data-search-js="search-2b6ce74ff89ae146.js" data-settings-js="settings-4313503d2e1961c2.js" ><script src="../static.files/storage-f2adc0d6ca4d09fb.js"></script><script defer src="sidebar-items.js"></script><script defer src="../static.files/main-305769736d49e732.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-feafe1bb7466e4bd.css"></noscript><link rel="alternate icon" type="image/png" href="../static.files/favicon-16x16-8b506e7a72182f1c.png"><link rel="alternate icon" type="image/png" href="../static.files/favicon-32x32-422f7d1d52889060.png"><link rel="icon" type="image/svg+xml" href="../static.files/favicon-2c020d218678b618.svg"></head><body class="rustdoc struct"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle">&#9776;</button></nav><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../syn/index.html">syn</a><span class="version">2.0.48</span></h2></div><h2 class="location"><a href="#">Attribute</a></h2><div class="sidebar-elems"><section><h3><a href="#fields">Fields</a></h3><ul class="block structfield"><li><a href="#structfield.bracket_token">bracket_token</a></li><li><a href="#structfield.meta">meta</a></li><li><a href="#structfield.pound_token">pound_token</a></li><li><a href="#structfield.style">style</a></li></ul><h3><a href="#implementations">Methods</a></h3><ul class="block method"><li><a href="#method.parse_args">parse_args</a></li><li><a href="#method.parse_args_with">parse_args_with</a></li><li><a href="#method.parse_inner">parse_inner</a></li><li><a href="#method.parse_nested_meta">parse_nested_meta</a></li><li><a href="#method.parse_outer">parse_outer</a></li><li><a href="#method.path">path</a></li></ul><h3><a href="#trait-implementations">Trait Implementations</a></h3><ul class="block trait-implementation"><li><a href="#impl-Clone-for-Attribute">Clone</a></li><li><a href="#impl-Debug-for-Attribute">Debug</a></li><li><a href="#impl-Eq-for-Attribute">Eq</a></li><li><a href="#impl-Hash-for-Attribute">Hash</a></li><li><a href="#impl-PartialEq-for-Attribute">PartialEq</a></li><li><a href="#impl-ToTokens-for-Attribute">ToTokens</a></li></ul><h3><a href="#synthetic-implementations">Auto Trait Implementations</a></h3><ul class="block synthetic-implementation"><li><a href="#impl-Send-for-Attribute">!Send</a></li><li><a href="#impl-Sync-for-Attribute">!Sync</a></li><li><a href="#impl-RefUnwindSafe-for-Attribute">RefUnwindSafe</a></li><li><a href="#impl-Unpin-for-Attribute">Unpin</a></li><li><a href="#impl-UnwindSafe-for-Attribute">UnwindSafe</a></li></ul><h3><a href="#blanket-implementations">Blanket Implementations</a></h3><ul class="block blanket-implementation"><li><a href="#impl-Any-for-T">Any</a></li><li><a href="#impl-Borrow%3CT%3E-for-T">Borrow&lt;T&gt;</a></li><li><a href="#impl-BorrowMut%3CT%3E-for-T">BorrowMut&lt;T&gt;</a></li><li><a href="#impl-From%3CT%3E-for-T">From&lt;T&gt;</a></li><li><a href="#impl-Into%3CU%3E-for-T">Into&lt;U&gt;</a></li><li><a href="#impl-Spanned-for-T">Spanned</a></li><li><a href="#impl-ToOwned-for-T">ToOwned</a></li><li><a href="#impl-TryFrom%3CU%3E-for-T">TryFrom&lt;U&gt;</a></li><li><a href="#impl-TryInto%3CU%3E-for-T">TryInto&lt;U&gt;</a></li></ul></section><h2><a href="index.html">In crate syn</a></h2></div></nav><div class="sidebar-resizer"></div>
<main><div class="width-limiter"><nav class="sub"><form class="search-form"><span></span><div id="sidebar-button" tabindex="-1"><a href="../syn/all.html" title="show sidebar"></a></div><input class="search-input" name="search" aria-label="Run search in the documentation" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" tabindex="-1"><a href="../help.html" title="help">?</a></div><div id="settings-menu" tabindex="-1"><a href="../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../static.files/wheel-7b819b6101059cd0.svg"></a></div></form></nav><section id="main-content" class="content"><div class="main-heading"><h1>Struct <a href="index.html">syn</a>::<wbr><a class="struct" href="#">Attribute</a><button id="copy-path" title="Copy item path to clipboard"><img src="../static.files/clipboard-7571035ce49a181d.svg" width="19" height="18" alt="Copy item path"></button></h1><span class="out-of-band"><a class="src" href="../src/syn/attr.rs.html#11-171">source</a> · <button id="toggle-all-docs" title="collapse all docs">[<span>&#x2212;</span>]</button></span></div><pre class="rust item-decl"><code>pub struct Attribute {
pub pound_token: <a class="struct" href="token/struct.Pound.html" title="struct syn::token::Pound">Pound</a>,
pub style: <a class="enum" href="enum.AttrStyle.html" title="enum syn::AttrStyle">AttrStyle</a>,
pub bracket_token: <a class="struct" href="token/struct.Bracket.html" title="struct syn::token::Bracket">Bracket</a>,
pub meta: <a class="enum" href="enum.Meta.html" title="enum syn::Meta">Meta</a>,
}</code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>An attribute, like <code>#[repr(transparent)]</code>.</p>
<br>
<h2 id="syntax"><a href="#syntax">Syntax</a></h2>
<p>Rust has six types of attributes.</p>
<ul>
<li>
<p>Outer attributes like <code>#[repr(transparent)]</code>. These appear outside or
in front of the item they describe.</p>
</li>
<li>
<p>Inner attributes like <code>#![feature(proc_macro)]</code>. These appear inside
of the item they describe, usually a module.</p>
</li>
<li>
<p>Outer one-line doc comments like <code>/// Example</code>.</p>
</li>
<li>
<p>Inner one-line doc comments like <code>//! Please file an issue</code>.</p>
</li>
<li>
<p>Outer documentation blocks <code>/** Example */</code>.</p>
</li>
<li>
<p>Inner documentation blocks <code>/*! Please file an issue */</code>.</p>
</li>
</ul>
<p>The <code>style</code> field of type <code>AttrStyle</code> distinguishes whether an attribute
is outer or inner.</p>
<p>Every attribute has a <code>path</code> that indicates the intended interpretation
of the rest of the attribute’s contents. The path and the optional
additional contents are represented together in the <code>meta</code> field of the
attribute in three possible varieties:</p>
<ul>
<li>
<p>Meta::Path — attributes whose information content conveys just a
path, for example the <code>#[test]</code> attribute.</p>
</li>
<li>
<p>Meta::List — attributes that carry arbitrary tokens after the
path, surrounded by a delimiter (parenthesis, bracket, or brace). For
example <code>#[derive(Copy)]</code> or <code>#[precondition(x &lt; 5)]</code>.</p>
</li>
<li>
<p>Meta::NameValue — attributes with an <code>=</code> sign after the path,
followed by a Rust expression. For example <code>#[path = &quot;sys/windows.rs&quot;]</code>.</p>
</li>
</ul>
<p>All doc comments are represented in the NameValue style with a path of
“doc”, as this is how they are processed by the compiler and by
<code>macro_rules!</code> macros.</p>
<div class="example-wrap"><pre class="language-text"><code>#[derive(Copy, Clone)]
~~~~~~Path
^^^^^^^^^^^^^^^^^^^Meta::List
#[path = &quot;sys/windows.rs&quot;]
~~~~Path
^^^^^^^^^^^^^^^^^^^^^^^Meta::NameValue
#[test]
^^^^Meta::Path
</code></pre></div><br>
<h2 id="parsing-from-tokens-to-attribute"><a href="#parsing-from-tokens-to-attribute">Parsing from tokens to Attribute</a></h2>
<p>This type does not implement the <a href="parse/trait.Parse.html" title="trait syn::parse::Parse"><code>Parse</code></a> trait and thus cannot be
parsed directly by <a href="parse/struct.ParseBuffer.html#method.parse" title="method syn::parse::ParseBuffer::parse"><code>ParseStream::parse</code></a>. Instead use
<a href="parse/struct.ParseBuffer.html#method.call" title="method syn::parse::ParseBuffer::call"><code>ParseStream::call</code></a> with one of the two parser functions
<a href="struct.Attribute.html#method.parse_outer" title="associated function syn::Attribute::parse_outer"><code>Attribute::parse_outer</code></a> or <a href="struct.Attribute.html#method.parse_inner" title="associated function syn::Attribute::parse_inner"><code>Attribute::parse_inner</code></a> depending on
which you intend to parse.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>syn::{Attribute, Ident, <span class="prelude-ty">Result</span>, Token};
<span class="kw">use </span>syn::parse::{Parse, ParseStream};
<span class="comment">// Parses a unit struct with attributes.
//
// #[path = "s.tmpl"]
// struct S;
</span><span class="kw">struct </span>UnitStruct {
attrs: Vec&lt;Attribute&gt;,
struct_token: <span class="macro">Token!</span>[<span class="kw">struct</span>],
name: Ident,
semi_token: <span class="macro">Token!</span>[;],
}
<span class="kw">impl </span>Parse <span class="kw">for </span>UnitStruct {
<span class="kw">fn </span>parse(input: ParseStream) -&gt; <span class="prelude-ty">Result</span>&lt;<span class="self">Self</span>&gt; {
<span class="prelude-val">Ok</span>(UnitStruct {
attrs: input.call(Attribute::parse_outer)<span class="question-mark">?</span>,
struct_token: input.parse()<span class="question-mark">?</span>,
name: input.parse()<span class="question-mark">?</span>,
semi_token: input.parse()<span class="question-mark">?</span>,
})
}
}</code></pre></div>
<p><br></p>
<h2 id="parsing-from-attribute-to-structured-arguments"><a href="#parsing-from-attribute-to-structured-arguments">Parsing from Attribute to structured arguments</a></h2>
<p>The grammar of attributes in Rust is very flexible, which makes the
syntax tree not that useful on its own. In particular, arguments of the
<code>Meta::List</code> variety of attribute are held in an arbitrary <code>tokens: TokenStream</code>. Macros are expected to check the <code>path</code> of the attribute,
decide whether they recognize it, and then parse the remaining tokens
according to whatever grammar they wish to require for that kind of
attribute. Use <a href="struct.Attribute.html#method.parse_args" title="method syn::Attribute::parse_args"><code>parse_args()</code></a> to parse those tokens into the expected
data structure.</p>
<p><br></p>
<h2 id="doc-comments"><a href="#doc-comments">Doc comments</a></h2>
<p>The compiler transforms doc comments, such as <code>/// comment</code> and <code>/*! comment */</code>, into attributes before macros are expanded. Each comment is
expanded into an attribute of the form <code>#[doc = r&quot;comment&quot;]</code>.</p>
<p>As an example, the following <code>mod</code> items are expanded identically:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">let </span>doc: ItemMod = <span class="macro">parse_quote! </span>{
<span class="doccomment">/// Single line doc comments
/// We write so many!
/**
* Multi-line comments...
* May span many lines
*/
</span><span class="kw">mod </span>example {
<span class="doccomment">//! Of course, they can be inner too
/*! And fit in a single line */
</span>}
};
<span class="kw">let </span>attr: ItemMod = <span class="macro">parse_quote! </span>{
<span class="attr">#[doc = <span class="string">r" Single line doc comments"</span>]
#[doc = <span class="string">r" We write so many!"</span>]
#[doc = <span class="string">r"
* Multi-line comments...
* May span many lines
"</span>]
</span><span class="kw">mod </span>example {
<span class="attr">#![doc = <span class="string">r" Of course, they can be inner too"</span>]
#![doc = <span class="string">r" And fit in a single line "</span>]
</span>}
};
<span class="macro">assert_eq!</span>(doc, attr);</code></pre></div>
</div></details><h2 id="fields" class="fields section-header">Fields<a href="#fields" class="anchor">§</a></h2><span id="structfield.pound_token" class="structfield section-header"><a href="#structfield.pound_token" class="anchor field">§</a><code>pound_token: <a class="struct" href="token/struct.Pound.html" title="struct syn::token::Pound">Pound</a></code></span><span id="structfield.style" class="structfield section-header"><a href="#structfield.style" class="anchor field">§</a><code>style: <a class="enum" href="enum.AttrStyle.html" title="enum syn::AttrStyle">AttrStyle</a></code></span><span id="structfield.bracket_token" class="structfield section-header"><a href="#structfield.bracket_token" class="anchor field">§</a><code>bracket_token: <a class="struct" href="token/struct.Bracket.html" title="struct syn::token::Bracket">Bracket</a></code></span><span id="structfield.meta" class="structfield section-header"><a href="#structfield.meta" class="anchor field">§</a><code>meta: <a class="enum" href="enum.Meta.html" title="enum syn::Meta">Meta</a></code></span><h2 id="implementations" class="section-header">Implementations<a href="#implementations" class="anchor">§</a></h2><div id="implementations-list"><details class="toggle implementors-toggle" open><summary><section id="impl-Attribute" class="impl"><a class="src rightside" href="../src/syn/attr.rs.html#173-419">source</a><a href="#impl-Attribute" class="anchor">§</a><h3 class="code-header">impl <a class="struct" href="struct.Attribute.html" title="struct syn::Attribute">Attribute</a></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.path" class="method"><a class="src rightside" href="../src/syn/attr.rs.html#178-180">source</a><h4 class="code-header">pub fn <a href="#method.path" class="fn">path</a>(&amp;self) -&gt; &amp;<a class="struct" href="struct.Path.html" title="struct syn::Path">Path</a></h4></section></summary><div class="docblock"><p>Returns the path that identifies the interpretation of this attribute.</p>
<p>For example this would return the <code>test</code> in <code>#[test]</code>, the <code>derive</code> in
<code>#[derive(Copy)]</code>, and the <code>path</code> in <code>#[path = &quot;sys/windows.rs&quot;]</code>.</p>
</div></details><details class="toggle method-toggle" open><summary><section id="method.parse_args" class="method"><a class="src rightside" href="../src/syn/attr.rs.html#214-216">source</a><h4 class="code-header">pub fn <a href="#method.parse_args" class="fn">parse_args</a>&lt;T: <a class="trait" href="parse/trait.Parse.html" title="trait syn::parse::Parse">Parse</a>&gt;(&amp;self) -&gt; <a class="type" href="parse/type.Result.html" title="type syn::parse::Result">Result</a>&lt;T&gt;</h4></section></summary><div class="docblock"><p>Parse the arguments to the attribute as a syntax tree.</p>
<p>This is similar to pulling out the <code>TokenStream</code> from <code>Meta::List</code> and
doing <code>syn::parse2::&lt;T&gt;(meta_list.tokens)</code>, except that using
<code>parse_args</code> the error message has a more useful span when <code>tokens</code> is
empty.</p>
<p>The surrounding delimiters are <em>not</em> included in the input to the
parser.</p>
<div class="example-wrap"><pre class="language-text"><code>#[my_attr(value &lt; 5)]
^^^^^^^^^ what gets parsed
</code></pre></div><h5 id="example"><a href="#example">Example</a></h5>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>syn::{parse_quote, Attribute, Expr};
<span class="kw">let </span>attr: Attribute = <span class="macro">parse_quote! </span>{
<span class="attr">#[precondition(value &lt; <span class="number">5</span>)]
</span>};
<span class="kw">if </span>attr.path().is_ident(<span class="string">"precondition"</span>) {
<span class="kw">let </span>precondition: Expr = attr.parse_args()<span class="question-mark">?</span>;
<span class="comment">// ...
</span>}</code></pre></div>
</div></details><details class="toggle method-toggle" open><summary><section id="method.parse_args_with" class="method"><a class="src rightside" href="../src/syn/attr.rs.html#237-258">source</a><h4 class="code-header">pub fn <a href="#method.parse_args_with" class="fn">parse_args_with</a>&lt;F: <a class="trait" href="parse/trait.Parser.html" title="trait syn::parse::Parser">Parser</a>&gt;(&amp;self, parser: F) -&gt; <a class="type" href="parse/type.Result.html" title="type syn::parse::Result">Result</a>&lt;F::<a class="associatedtype" href="parse/trait.Parser.html#associatedtype.Output" title="type syn::parse::Parser::Output">Output</a>&gt;</h4></section></summary><div class="docblock"><p>Parse the arguments to the attribute using the given parser.</p>
<h5 id="example-1"><a href="#example-1">Example</a></h5>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>syn::{parse_quote, Attribute};
<span class="kw">let </span>attr: Attribute = <span class="macro">parse_quote! </span>{
<span class="attr">#[inception { <span class="attr">#[brrrrrrraaaaawwwwrwrrrmrmrmmrmrmmmmm] </span>}]
};
<span class="kw">let </span>bwom = attr.parse_args_with(Attribute::parse_outer)<span class="question-mark">?</span>;
<span class="comment">// Attribute does not have a Parse impl, so we couldn't directly do:
// let bwom: Attribute = attr.parse_args()?;</span></code></pre></div>
</div></details><details class="toggle method-toggle" open><summary><section id="method.parse_nested_meta" class="method"><a class="src rightside" href="../src/syn/attr.rs.html#383-388">source</a><h4 class="code-header">pub fn <a href="#method.parse_nested_meta" class="fn">parse_nested_meta</a>(
&amp;self,
logic: impl <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/ops/function/trait.FnMut.html" title="trait core::ops::function::FnMut">FnMut</a>(<a class="struct" href="meta/struct.ParseNestedMeta.html" title="struct syn::meta::ParseNestedMeta">ParseNestedMeta</a>&lt;'_&gt;) -&gt; <a class="type" href="parse/type.Result.html" title="type syn::parse::Result">Result</a>&lt;<a class="primitive" href="https://doc.rust-lang.org/1.76.0/std/primitive.unit.html">()</a>&gt;
) -&gt; <a class="type" href="parse/type.Result.html" title="type syn::parse::Result">Result</a>&lt;<a class="primitive" href="https://doc.rust-lang.org/1.76.0/std/primitive.unit.html">()</a>&gt;</h4></section></summary><div class="docblock"><p>Parse the arguments to the attribute, expecting it to follow the
conventional structure used by most of Rust’s built-in attributes.</p>
<p>The <a href="https://doc.rust-lang.org/reference/attributes.html#meta-item-attribute-syntax"><em>Meta Item Attribute Syntax</em></a> section in the Rust reference
explains the convention in more detail. Not all attributes follow this
convention, so <a href="struct.Attribute.html#method.parse_args" title="method syn::Attribute::parse_args"><code>parse_args()</code></a> is available if you
need to parse arbitrarily goofy attribute syntax.</p>
<h5 id="example-2"><a href="#example-2">Example</a></h5>
<p>We’ll parse a struct, and then parse some of Rust’s <code>#[repr]</code> attribute
syntax.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>syn::{parenthesized, parse_quote, token, ItemStruct, LitInt};
<span class="kw">let </span>input: ItemStruct = <span class="macro">parse_quote! </span>{
<span class="attr">#[repr(C, align(<span class="number">4</span>))]
</span><span class="kw">pub struct </span>MyStruct(u16, u32);
};
<span class="kw">let </span><span class="kw-2">mut </span>repr_c = <span class="bool-val">false</span>;
<span class="kw">let </span><span class="kw-2">mut </span>repr_transparent = <span class="bool-val">false</span>;
<span class="kw">let </span><span class="kw-2">mut </span>repr_align = <span class="prelude-val">None</span>::&lt;usize&gt;;
<span class="kw">let </span><span class="kw-2">mut </span>repr_packed = <span class="prelude-val">None</span>::&lt;usize&gt;;
<span class="kw">for </span>attr <span class="kw">in </span><span class="kw-2">&amp;</span>input.attrs {
<span class="kw">if </span>attr.path().is_ident(<span class="string">"repr"</span>) {
attr.parse_nested_meta(|meta| {
<span class="comment">// #[repr(C)]
</span><span class="kw">if </span>meta.path.is_ident(<span class="string">"C"</span>) {
repr_c = <span class="bool-val">true</span>;
<span class="kw">return </span><span class="prelude-val">Ok</span>(());
}
<span class="comment">// #[repr(transparent)]
</span><span class="kw">if </span>meta.path.is_ident(<span class="string">"transparent"</span>) {
repr_transparent = <span class="bool-val">true</span>;
<span class="kw">return </span><span class="prelude-val">Ok</span>(());
}
<span class="comment">// #[repr(align(N))]
</span><span class="kw">if </span>meta.path.is_ident(<span class="string">"align"</span>) {
<span class="kw">let </span>content;
<span class="macro">parenthesized!</span>(content <span class="kw">in </span>meta.input);
<span class="kw">let </span>lit: LitInt = content.parse()<span class="question-mark">?</span>;
<span class="kw">let </span>n: usize = lit.base10_parse()<span class="question-mark">?</span>;
repr_align = <span class="prelude-val">Some</span>(n);
<span class="kw">return </span><span class="prelude-val">Ok</span>(());
}
<span class="comment">// #[repr(packed)] or #[repr(packed(N))], omitted N means 1
</span><span class="kw">if </span>meta.path.is_ident(<span class="string">"packed"</span>) {
<span class="kw">if </span>meta.input.peek(token::Paren) {
<span class="kw">let </span>content;
<span class="macro">parenthesized!</span>(content <span class="kw">in </span>meta.input);
<span class="kw">let </span>lit: LitInt = content.parse()<span class="question-mark">?</span>;
<span class="kw">let </span>n: usize = lit.base10_parse()<span class="question-mark">?</span>;
repr_packed = <span class="prelude-val">Some</span>(n);
} <span class="kw">else </span>{
repr_packed = <span class="prelude-val">Some</span>(<span class="number">1</span>);
}
<span class="kw">return </span><span class="prelude-val">Ok</span>(());
}
<span class="prelude-val">Err</span>(meta.error(<span class="string">"unrecognized repr"</span>))
})<span class="question-mark">?</span>;
}
}</code></pre></div>
<h5 id="alternatives"><a href="#alternatives">Alternatives</a></h5>
<p>In some cases, for attributes which have nested layers of structured
content, the following less flexible approach might be more convenient:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>syn::punctuated::Punctuated;
<span class="kw">use </span>syn::{parenthesized, token, Error, LitInt, Meta, Token};
<span class="kw">let </span><span class="kw-2">mut </span>repr_c = <span class="bool-val">false</span>;
<span class="kw">let </span><span class="kw-2">mut </span>repr_transparent = <span class="bool-val">false</span>;
<span class="kw">let </span><span class="kw-2">mut </span>repr_align = <span class="prelude-val">None</span>::&lt;usize&gt;;
<span class="kw">let </span><span class="kw-2">mut </span>repr_packed = <span class="prelude-val">None</span>::&lt;usize&gt;;
<span class="kw">for </span>attr <span class="kw">in </span><span class="kw-2">&amp;</span>input.attrs {
<span class="kw">if </span>attr.path().is_ident(<span class="string">"repr"</span>) {
<span class="kw">let </span>nested = attr.parse_args_with(Punctuated::&lt;Meta, <span class="macro">Token!</span>[,]&gt;::parse_terminated)<span class="question-mark">?</span>;
<span class="kw">for </span>meta <span class="kw">in </span>nested {
<span class="kw">match </span>meta {
<span class="comment">// #[repr(C)]
</span>Meta::Path(path) <span class="kw">if </span>path.is_ident(<span class="string">"C"</span>) =&gt; {
repr_c = <span class="bool-val">true</span>;
}
<span class="comment">// #[repr(align(N))]
</span>Meta::List(meta) <span class="kw">if </span>meta.path.is_ident(<span class="string">"align"</span>) =&gt; {
<span class="kw">let </span>lit: LitInt = meta.parse_args()<span class="question-mark">?</span>;
<span class="kw">let </span>n: usize = lit.base10_parse()<span class="question-mark">?</span>;
repr_align = <span class="prelude-val">Some</span>(n);
}
<span class="comment">/* ... */
</span><span class="kw">_ </span>=&gt; {
<span class="kw">return </span><span class="prelude-val">Err</span>(Error::new_spanned(meta, <span class="string">"unrecognized repr"</span>));
}
}
}
}
}</code></pre></div>
</div></details><details class="toggle method-toggle" open><summary><section id="method.parse_outer" class="method"><a class="src rightside" href="../src/syn/attr.rs.html#398-404">source</a><h4 class="code-header">pub fn <a href="#method.parse_outer" class="fn">parse_outer</a>(input: <a class="type" href="parse/type.ParseStream.html" title="type syn::parse::ParseStream">ParseStream</a>&lt;'_&gt;) -&gt; <a class="type" href="parse/type.Result.html" title="type syn::parse::Result">Result</a>&lt;<a class="struct" href="https://doc.rust-lang.org/1.76.0/alloc/vec/struct.Vec.html" title="struct alloc::vec::Vec">Vec</a>&lt;Self&gt;&gt;</h4></section></summary><div class="docblock"><p>Parses zero or more outer attributes from the stream.</p>
<h5 id="example-3"><a href="#example-3">Example</a></h5>
<p>See
<a href="#parsing-from-tokens-to-attribute"><em>Parsing from tokens to Attribute</em></a>.</p>
</div></details><details class="toggle method-toggle" open><summary><section id="method.parse_inner" class="method"><a class="src rightside" href="../src/syn/attr.rs.html#414-418">source</a><h4 class="code-header">pub fn <a href="#method.parse_inner" class="fn">parse_inner</a>(input: <a class="type" href="parse/type.ParseStream.html" title="type syn::parse::ParseStream">ParseStream</a>&lt;'_&gt;) -&gt; <a class="type" href="parse/type.Result.html" title="type syn::parse::Result">Result</a>&lt;<a class="struct" href="https://doc.rust-lang.org/1.76.0/alloc/vec/struct.Vec.html" title="struct alloc::vec::Vec">Vec</a>&lt;Self&gt;&gt;</h4></section></summary><div class="docblock"><p>Parses zero or more inner attributes from the stream.</p>
<h5 id="example-4"><a href="#example-4">Example</a></h5>
<p>See
<a href="#parsing-from-tokens-to-attribute"><em>Parsing from tokens to Attribute</em></a>.</p>
</div></details></div></details></div><h2 id="trait-implementations" class="section-header">Trait Implementations<a href="#trait-implementations" class="anchor">§</a></h2><div id="trait-implementations-list"><details class="toggle implementors-toggle" open><summary><section id="impl-Clone-for-Attribute" class="impl"><a class="src rightside" href="../src/syn/gen/clone.rs.html#78-87">source</a><a href="#impl-Clone-for-Attribute" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a> for <a class="struct" href="struct.Attribute.html" title="struct syn::Attribute">Attribute</a></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.clone" class="method trait-impl"><a class="src rightside" href="../src/syn/gen/clone.rs.html#79-86">source</a><a href="#method.clone" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/core/clone/trait.Clone.html#tymethod.clone" class="fn">clone</a>(&amp;self) -&gt; Self</h4></section></summary><div class='docblock'>Returns a copy of the value. <a href="https://doc.rust-lang.org/1.76.0/core/clone/trait.Clone.html#tymethod.clone">Read more</a></div></details><details class="toggle method-toggle" open><summary><section id="method.clone_from" class="method trait-impl"><span class="rightside"><span class="since" title="Stable since Rust version 1.0.0">1.0.0</span> · <a class="src" href="https://doc.rust-lang.org/1.76.0/src/core/clone.rs.html#169">source</a></span><a href="#method.clone_from" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/core/clone/trait.Clone.html#method.clone_from" class="fn">clone_from</a>(&amp;mut self, source: <a class="primitive" href="https://doc.rust-lang.org/1.76.0/std/primitive.reference.html">&amp;Self</a>)</h4></section></summary><div class='docblock'>Performs copy-assignment from <code>source</code>. <a href="https://doc.rust-lang.org/1.76.0/core/clone/trait.Clone.html#method.clone_from">Read more</a></div></details></div></details><details class="toggle implementors-toggle" open><summary><section id="impl-Debug-for-Attribute" class="impl"><a class="src rightside" href="../src/syn/gen/debug.rs.html#88-97">source</a><a href="#impl-Debug-for-Attribute" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/fmt/trait.Debug.html" title="trait core::fmt::Debug">Debug</a> for <a class="struct" href="struct.Attribute.html" title="struct syn::Attribute">Attribute</a></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.fmt" class="method trait-impl"><a class="src rightside" href="../src/syn/gen/debug.rs.html#89-96">source</a><a href="#method.fmt" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/core/fmt/trait.Debug.html#tymethod.fmt" class="fn">fmt</a>(&amp;self, formatter: &amp;mut <a class="struct" href="https://doc.rust-lang.org/1.76.0/core/fmt/struct.Formatter.html" title="struct core::fmt::Formatter">Formatter</a>&lt;'_&gt;) -&gt; <a class="type" href="https://doc.rust-lang.org/1.76.0/core/fmt/type.Result.html" title="type core::fmt::Result">Result</a></h4></section></summary><div class='docblock'>Formats the value using the given formatter. <a href="https://doc.rust-lang.org/1.76.0/core/fmt/trait.Debug.html#tymethod.fmt">Read more</a></div></details></div></details><details class="toggle implementors-toggle" open><summary><section id="impl-Hash-for-Attribute" class="impl"><a class="src rightside" href="../src/syn/gen/hash.rs.html#86-94">source</a><a href="#impl-Hash-for-Attribute" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/hash/trait.Hash.html" title="trait core::hash::Hash">Hash</a> for <a class="struct" href="struct.Attribute.html" title="struct syn::Attribute">Attribute</a></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.hash" class="method trait-impl"><a class="src rightside" href="../src/syn/gen/hash.rs.html#87-93">source</a><a href="#method.hash" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/core/hash/trait.Hash.html#tymethod.hash" class="fn">hash</a>&lt;H&gt;(&amp;self, state: <a class="primitive" href="https://doc.rust-lang.org/1.76.0/std/primitive.reference.html">&amp;mut H</a>)<div class="where">where
H: <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/hash/trait.Hasher.html" title="trait core::hash::Hasher">Hasher</a>,</div></h4></section></summary><div class='docblock'>Feeds this value into the given <a href="https://doc.rust-lang.org/1.76.0/core/hash/trait.Hasher.html" title="trait core::hash::Hasher"><code>Hasher</code></a>. <a href="https://doc.rust-lang.org/1.76.0/core/hash/trait.Hash.html#tymethod.hash">Read more</a></div></details><details class="toggle method-toggle" open><summary><section id="method.hash_slice" class="method trait-impl"><span class="rightside"><span class="since" title="Stable since Rust version 1.3.0">1.3.0</span> · <a class="src" href="https://doc.rust-lang.org/1.76.0/src/core/hash/mod.rs.html#238-240">source</a></span><a href="#method.hash_slice" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/core/hash/trait.Hash.html#method.hash_slice" class="fn">hash_slice</a>&lt;H&gt;(data: &amp;<a class="primitive" href="https://doc.rust-lang.org/1.76.0/std/primitive.slice.html">[Self]</a>, state: <a class="primitive" href="https://doc.rust-lang.org/1.76.0/std/primitive.reference.html">&amp;mut H</a>)<div class="where">where
H: <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/hash/trait.Hasher.html" title="trait core::hash::Hasher">Hasher</a>,
Self: <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</div></h4></section></summary><div class='docblock'>Feeds a slice of this type into the given <a href="https://doc.rust-lang.org/1.76.0/core/hash/trait.Hasher.html" title="trait core::hash::Hasher"><code>Hasher</code></a>. <a href="https://doc.rust-lang.org/1.76.0/core/hash/trait.Hash.html#method.hash_slice">Read more</a></div></details></div></details><details class="toggle implementors-toggle" open><summary><section id="impl-PartialEq-for-Attribute" class="impl"><a class="src rightside" href="../src/syn/gen/eq.rs.html#79-83">source</a><a href="#impl-PartialEq-for-Attribute" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/cmp/trait.PartialEq.html" title="trait core::cmp::PartialEq">PartialEq</a> for <a class="struct" href="struct.Attribute.html" title="struct syn::Attribute">Attribute</a></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.eq" class="method trait-impl"><a class="src rightside" href="../src/syn/gen/eq.rs.html#80-82">source</a><a href="#method.eq" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/core/cmp/trait.PartialEq.html#tymethod.eq" class="fn">eq</a>(&amp;self, other: <a class="primitive" href="https://doc.rust-lang.org/1.76.0/std/primitive.reference.html">&amp;Self</a>) -&gt; <a class="primitive" href="https://doc.rust-lang.org/1.76.0/std/primitive.bool.html">bool</a></h4></section></summary><div class='docblock'>This method tests for <code>self</code> and <code>other</code> values to be equal, and is used
by <code>==</code>.</div></details><details class="toggle method-toggle" open><summary><section id="method.ne" class="method trait-impl"><span class="rightside"><span class="since" title="Stable since Rust version 1.0.0">1.0.0</span> · <a class="src" href="https://doc.rust-lang.org/1.76.0/src/core/cmp.rs.html#242">source</a></span><a href="#method.ne" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/core/cmp/trait.PartialEq.html#method.ne" class="fn">ne</a>(&amp;self, other: <a class="primitive" href="https://doc.rust-lang.org/1.76.0/std/primitive.reference.html">&amp;Rhs</a>) -&gt; <a class="primitive" href="https://doc.rust-lang.org/1.76.0/std/primitive.bool.html">bool</a></h4></section></summary><div class='docblock'>This method tests for <code>!=</code>. The default implementation is almost always
sufficient, and should not be overridden without very good reason.</div></details></div></details><details class="toggle implementors-toggle" open><summary><section id="impl-ToTokens-for-Attribute" class="impl"><a class="src rightside" href="../src/syn/attr.rs.html#748-758">source</a><a href="#impl-ToTokens-for-Attribute" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="../quote/to_tokens/trait.ToTokens.html" title="trait quote::to_tokens::ToTokens">ToTokens</a> for <a class="struct" href="struct.Attribute.html" title="struct syn::Attribute">Attribute</a></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.to_tokens" class="method trait-impl"><a class="src rightside" href="../src/syn/attr.rs.html#749-757">source</a><a href="#method.to_tokens" class="anchor">§</a><h4 class="code-header">fn <a href="../quote/to_tokens/trait.ToTokens.html#tymethod.to_tokens" class="fn">to_tokens</a>(&amp;self, tokens: &amp;mut <a class="struct" href="../proc_macro2/struct.TokenStream.html" title="struct proc_macro2::TokenStream">TokenStream</a>)</h4></section></summary><div class='docblock'>Write <code>self</code> to the given <code>TokenStream</code>. <a href="../quote/to_tokens/trait.ToTokens.html#tymethod.to_tokens">Read more</a></div></details><details class="toggle method-toggle" open><summary><section id="method.to_token_stream" class="method trait-impl"><a class="src rightside" href="../src/quote/to_tokens.rs.html#59">source</a><a href="#method.to_token_stream" class="anchor">§</a><h4 class="code-header">fn <a href="../quote/to_tokens/trait.ToTokens.html#method.to_token_stream" class="fn">to_token_stream</a>(&amp;self) -&gt; <a class="struct" href="../proc_macro2/struct.TokenStream.html" title="struct proc_macro2::TokenStream">TokenStream</a></h4></section></summary><div class='docblock'>Convert <code>self</code> directly into a <code>TokenStream</code> object. <a href="../quote/to_tokens/trait.ToTokens.html#method.to_token_stream">Read more</a></div></details><details class="toggle method-toggle" open><summary><section id="method.into_token_stream" class="method trait-impl"><a class="src rightside" href="../src/quote/to_tokens.rs.html#69-71">source</a><a href="#method.into_token_stream" class="anchor">§</a><h4 class="code-header">fn <a href="../quote/to_tokens/trait.ToTokens.html#method.into_token_stream" class="fn">into_token_stream</a>(self) -&gt; <a class="struct" href="../proc_macro2/struct.TokenStream.html" title="struct proc_macro2::TokenStream">TokenStream</a><div class="where">where
Self: <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</div></h4></section></summary><div class='docblock'>Convert <code>self</code> directly into a <code>TokenStream</code> object. <a href="../quote/to_tokens/trait.ToTokens.html#method.into_token_stream">Read more</a></div></details></div></details><section id="impl-Eq-for-Attribute" class="impl"><a class="src rightside" href="../src/syn/gen/eq.rs.html#76">source</a><a href="#impl-Eq-for-Attribute" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/cmp/trait.Eq.html" title="trait core::cmp::Eq">Eq</a> for <a class="struct" href="struct.Attribute.html" title="struct syn::Attribute">Attribute</a></h3></section></div><h2 id="synthetic-implementations" class="section-header">Auto Trait Implementations<a href="#synthetic-implementations" class="anchor">§</a></h2><div id="synthetic-implementations-list"><section id="impl-RefUnwindSafe-for-Attribute" class="impl"><a href="#impl-RefUnwindSafe-for-Attribute" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/panic/unwind_safe/trait.RefUnwindSafe.html" title="trait core::panic::unwind_safe::RefUnwindSafe">RefUnwindSafe</a> for <a class="struct" href="struct.Attribute.html" title="struct syn::Attribute">Attribute</a></h3></section><section id="impl-Send-for-Attribute" class="impl"><a href="#impl-Send-for-Attribute" class="anchor">§</a><h3 class="code-header">impl !<a class="trait" href="https://doc.rust-lang.org/1.76.0/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a> for <a class="struct" href="struct.Attribute.html" title="struct syn::Attribute">Attribute</a></h3></section><section id="impl-Sync-for-Attribute" class="impl"><a href="#impl-Sync-for-Attribute" class="anchor">§</a><h3 class="code-header">impl !<a class="trait" href="https://doc.rust-lang.org/1.76.0/core/marker/trait.Sync.html" title="trait core::marker::Sync">Sync</a> for <a class="struct" href="struct.Attribute.html" title="struct syn::Attribute">Attribute</a></h3></section><section id="impl-Unpin-for-Attribute" class="impl"><a href="#impl-Unpin-for-Attribute" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/marker/trait.Unpin.html" title="trait core::marker::Unpin">Unpin</a> for <a class="struct" href="struct.Attribute.html" title="struct syn::Attribute">Attribute</a></h3></section><section id="impl-UnwindSafe-for-Attribute" class="impl"><a href="#impl-UnwindSafe-for-Attribute" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/panic/unwind_safe/trait.UnwindSafe.html" title="trait core::panic::unwind_safe::UnwindSafe">UnwindSafe</a> for <a class="struct" href="struct.Attribute.html" title="struct syn::Attribute">Attribute</a></h3></section></div><h2 id="blanket-implementations" class="section-header">Blanket Implementations<a href="#blanket-implementations" class="anchor">§</a></h2><div id="blanket-implementations-list"><details class="toggle implementors-toggle"><summary><section id="impl-Any-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/core/any.rs.html#140">source</a><a href="#impl-Any-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/any/trait.Any.html" title="trait core::any::Any">Any</a> for T<div class="where">where
T: 'static + ?<a class="trait" href="https://doc.rust-lang.org/1.76.0/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</div></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.type_id" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/core/any.rs.html#141">source</a><a href="#method.type_id" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/core/any/trait.Any.html#tymethod.type_id" class="fn">type_id</a>(&amp;self) -&gt; <a class="struct" href="https://doc.rust-lang.org/1.76.0/core/any/struct.TypeId.html" title="struct core::any::TypeId">TypeId</a></h4></section></summary><div class='docblock'>Gets the <code>TypeId</code> of <code>self</code>. <a href="https://doc.rust-lang.org/1.76.0/core/any/trait.Any.html#tymethod.type_id">Read more</a></div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-Borrow%3CT%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/core/borrow.rs.html#208">source</a><a href="#impl-Borrow%3CT%3E-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/borrow/trait.Borrow.html" title="trait core::borrow::Borrow">Borrow</a>&lt;T&gt; for T<div class="where">where
T: ?<a class="trait" href="https://doc.rust-lang.org/1.76.0/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</div></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.borrow" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/core/borrow.rs.html#210">source</a><a href="#method.borrow" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/core/borrow/trait.Borrow.html#tymethod.borrow" class="fn">borrow</a>(&amp;self) -&gt; <a class="primitive" href="https://doc.rust-lang.org/1.76.0/std/primitive.reference.html">&amp;T</a></h4></section></summary><div class='docblock'>Immutably borrows from an owned value. <a href="https://doc.rust-lang.org/1.76.0/core/borrow/trait.Borrow.html#tymethod.borrow">Read more</a></div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-BorrowMut%3CT%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/core/borrow.rs.html#216">source</a><a href="#impl-BorrowMut%3CT%3E-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/borrow/trait.BorrowMut.html" title="trait core::borrow::BorrowMut">BorrowMut</a>&lt;T&gt; for T<div class="where">where
T: ?<a class="trait" href="https://doc.rust-lang.org/1.76.0/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</div></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.borrow_mut" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/core/borrow.rs.html#217">source</a><a href="#method.borrow_mut" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut" class="fn">borrow_mut</a>(&amp;mut self) -&gt; <a class="primitive" href="https://doc.rust-lang.org/1.76.0/std/primitive.reference.html">&amp;mut T</a></h4></section></summary><div class='docblock'>Mutably borrows from an owned value. <a href="https://doc.rust-lang.org/1.76.0/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut">Read more</a></div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-From%3CT%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/core/convert/mod.rs.html#763">source</a><a href="#impl-From%3CT%3E-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/convert/trait.From.html" title="trait core::convert::From">From</a>&lt;T&gt; for T</h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.from" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/core/convert/mod.rs.html#766">source</a><a href="#method.from" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/core/convert/trait.From.html#tymethod.from" class="fn">from</a>(t: T) -&gt; T</h4></section></summary><div class="docblock"><p>Returns the argument unchanged.</p>
</div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-Into%3CU%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/core/convert/mod.rs.html#747-749">source</a><a href="#impl-Into%3CU%3E-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T, U&gt; <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/convert/trait.Into.html" title="trait core::convert::Into">Into</a>&lt;U&gt; for T<div class="where">where
U: <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/convert/trait.From.html" title="trait core::convert::From">From</a>&lt;T&gt;,</div></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.into" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/core/convert/mod.rs.html#756">source</a><a href="#method.into" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/core/convert/trait.Into.html#tymethod.into" class="fn">into</a>(self) -&gt; U</h4></section></summary><div class="docblock"><p>Calls <code>U::from(self)</code>.</p>
<p>That is, this conversion is whatever the implementation of
<code><a href="https://doc.rust-lang.org/1.76.0/core/convert/trait.From.html" title="trait core::convert::From">From</a>&lt;T&gt; for U</code> chooses to do.</p>
</div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-Spanned-for-T" class="impl"><a class="src rightside" href="../src/syn/spanned.rs.html#104-108">source</a><a href="#impl-Spanned-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T&gt; <a class="trait" href="spanned/trait.Spanned.html" title="trait syn::spanned::Spanned">Spanned</a> for T<div class="where">where
T: Spanned + ?<a class="trait" href="https://doc.rust-lang.org/1.76.0/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,</div></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.span" class="method trait-impl"><a class="src rightside" href="../src/syn/spanned.rs.html#105-107">source</a><a href="#method.span" class="anchor">§</a><h4 class="code-header">fn <a href="spanned/trait.Spanned.html#tymethod.span" class="fn">span</a>(&amp;self) -&gt; <a class="struct" href="../proc_macro2/struct.Span.html" title="struct proc_macro2::Span">Span</a></h4></section></summary><div class='docblock'>Returns a <code>Span</code> covering the complete contents of this syntax tree
node, or <a href="../proc_macro2/struct.Span.html#method.call_site" title="associated function proc_macro2::Span::call_site"><code>Span::call_site()</code></a> if this node is empty.</div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-ToOwned-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/alloc/borrow.rs.html#83-85">source</a><a href="#impl-ToOwned-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/1.76.0/alloc/borrow/trait.ToOwned.html" title="trait alloc::borrow::ToOwned">ToOwned</a> for T<div class="where">where
T: <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a>,</div></h3></section></summary><div class="impl-items"><details class="toggle" open><summary><section id="associatedtype.Owned" class="associatedtype trait-impl"><a href="#associatedtype.Owned" class="anchor">§</a><h4 class="code-header">type <a href="https://doc.rust-lang.org/1.76.0/alloc/borrow/trait.ToOwned.html#associatedtype.Owned" class="associatedtype">Owned</a> = T</h4></section></summary><div class='docblock'>The resulting type after obtaining ownership.</div></details><details class="toggle method-toggle" open><summary><section id="method.to_owned" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/alloc/borrow.rs.html#88">source</a><a href="#method.to_owned" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/alloc/borrow/trait.ToOwned.html#tymethod.to_owned" class="fn">to_owned</a>(&amp;self) -&gt; T</h4></section></summary><div class='docblock'>Creates owned data from borrowed data, usually by cloning. <a href="https://doc.rust-lang.org/1.76.0/alloc/borrow/trait.ToOwned.html#tymethod.to_owned">Read more</a></div></details><details class="toggle method-toggle" open><summary><section id="method.clone_into" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/alloc/borrow.rs.html#92">source</a><a href="#method.clone_into" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/alloc/borrow/trait.ToOwned.html#method.clone_into" class="fn">clone_into</a>(&amp;self, target: <a class="primitive" href="https://doc.rust-lang.org/1.76.0/std/primitive.reference.html">&amp;mut T</a>)</h4></section></summary><div class='docblock'>Uses borrowed data to replace owned data, usually by cloning. <a href="https://doc.rust-lang.org/1.76.0/alloc/borrow/trait.ToOwned.html#method.clone_into">Read more</a></div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-TryFrom%3CU%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/core/convert/mod.rs.html#803-805">source</a><a href="#impl-TryFrom%3CU%3E-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T, U&gt; <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a>&lt;U&gt; for T<div class="where">where
U: <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/convert/trait.Into.html" title="trait core::convert::Into">Into</a>&lt;T&gt;,</div></h3></section></summary><div class="impl-items"><details class="toggle" open><summary><section id="associatedtype.Error" class="associatedtype trait-impl"><a href="#associatedtype.Error" class="anchor">§</a><h4 class="code-header">type <a href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html#associatedtype.Error" class="associatedtype">Error</a> = <a class="enum" href="https://doc.rust-lang.org/1.76.0/core/convert/enum.Infallible.html" title="enum core::convert::Infallible">Infallible</a></h4></section></summary><div class='docblock'>The type returned in the event of a conversion error.</div></details><details class="toggle method-toggle" open><summary><section id="method.try_from" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/core/convert/mod.rs.html#810">source</a><a href="#method.try_from" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html#tymethod.try_from" class="fn">try_from</a>(value: U) -&gt; <a class="enum" href="https://doc.rust-lang.org/1.76.0/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;T, &lt;T as <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a>&lt;U&gt;&gt;::<a class="associatedtype" href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a>&gt;</h4></section></summary><div class='docblock'>Performs the conversion.</div></details></div></details><details class="toggle implementors-toggle"><summary><section id="impl-TryInto%3CU%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/core/convert/mod.rs.html#788-790">source</a><a href="#impl-TryInto%3CU%3E-for-T" class="anchor">§</a><h3 class="code-header">impl&lt;T, U&gt; <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryInto.html" title="trait core::convert::TryInto">TryInto</a>&lt;U&gt; for T<div class="where">where
U: <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a>&lt;T&gt;,</div></h3></section></summary><div class="impl-items"><details class="toggle" open><summary><section id="associatedtype.Error-1" class="associatedtype trait-impl"><a href="#associatedtype.Error-1" class="anchor">§</a><h4 class="code-header">type <a href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryInto.html#associatedtype.Error" class="associatedtype">Error</a> = &lt;U as <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a>&lt;T&gt;&gt;::<a class="associatedtype" href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a></h4></section></summary><div class='docblock'>The type returned in the event of a conversion error.</div></details><details class="toggle method-toggle" open><summary><section id="method.try_into" class="method trait-impl"><a class="src rightside" href="https://doc.rust-lang.org/1.76.0/src/core/convert/mod.rs.html#795">source</a><a href="#method.try_into" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryInto.html#tymethod.try_into" class="fn">try_into</a>(self) -&gt; <a class="enum" href="https://doc.rust-lang.org/1.76.0/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;U, &lt;U as <a class="trait" href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a>&lt;T&gt;&gt;::<a class="associatedtype" href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a>&gt;</h4></section></summary><div class='docblock'>Performs the conversion.</div></details></div></details></div></section></div></main></body></html>
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