edg-l/edlang
1
1
Fork 0
mirror of https://github.com/edg-l/edlang.git synced 2024-11-23 00:18:24 +00:00
Code Issues Packages Projects Releases Wiki Activity
edlang/syn/struct.Attribute.html
edg-l fea68beee3 deploy: 637aa8e229
2024-05-07 06:31:16 +00:00

305 lines
58 KiB
HTML
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!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><script> if (window.location.protocol !== "file:") document.write(`<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">`)</script><link rel="stylesheet" href="../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../static.files/rustdoc-e935ef01ae1c1829.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="1.78.0 (9b00956e5 2024-04-29)" data-channel="1.78.0" data-search-js="search-42d8da7a6b9792c2.js" data-settings-js="settings-4313503d2e1961c2.js" ><script src="../static.files/storage-4c98445ec4002617.js"></script><script defer src="sidebar-items.js"></script><script defer src="../static.files/main-12cf3b4f4f9dc36d.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-04d5337699b92874.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" title="show sidebar"></button></nav><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../syn/index.html">syn</a><span class="version">2.0.61</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-Freeze-for-Attribute">Freeze</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#19-179">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 class="doc-anchor" href="#syntax">§</a>Syntax</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 class="doc-anchor" href="#parsing-from-tokens-to-attribute">§</a>Parsing from tokens to Attribute</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 class="doc-anchor" href="#parsing-from-attribute-to-structured-arguments">§</a>Parsing from Attribute to structured arguments</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 class="doc-anchor" href="#doc-comments">§</a>Doc comments</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#181-427">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#186-188">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#222-224">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 class="doc-anchor" href="#example">§</a>Example</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#245-266">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 class="doc-anchor" href="#example-1">§</a>Example</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#391-396">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/1.78.0/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/1.78.0/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/1.78.0/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 class="doc-anchor" href="#example-2">§</a>Example</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 class="doc-anchor" href="#alternatives">§</a>Alternatives</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#406-412">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/1.78.0/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 class="doc-anchor" href="#example-3">§</a>Example</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#422-426">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/1.78.0/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 class="doc-anchor" href="#example-4">§</a>Example</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#77-86">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/1.78.0/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#78-85">source</a><a href="#method.clone" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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#89-98">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/1.78.0/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#90-97">source</a><a href="#method.fmt" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.78.0/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/1.78.0/core/fmt/struct.Formatter.html" title="struct core::fmt::Formatter">Formatter</a>&lt;'_&gt;) -&gt; <a class="type" href="https://doc.rust-lang.org/1.78.0/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/1.78.0/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#85-93">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/1.78.0/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#86-92">source</a><a href="#method.hash" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.78.0/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/1.78.0/std/primitive.reference.html">&amp;mut H</a>)<div class="where">where
H: <a class="trait" href="https://doc.rust-lang.org/1.78.0/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/1.78.0/core/hash/trait.Hasher.html" title="trait core::hash::Hasher"><code>Hasher</code></a>. <a href="https://doc.rust-lang.org/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/std/primitive.slice.html">[Self]</a>, state: <a class="primitive" href="https://doc.rust-lang.org/1.78.0/std/primitive.reference.html">&amp;mut H</a>)<div class="where">where
H: <a class="trait" href="https://doc.rust-lang.org/1.78.0/core/hash/trait.Hasher.html" title="trait core::hash::Hasher">Hasher</a>,
Self: <a class="trait" href="https://doc.rust-lang.org/1.78.0/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/1.78.0/core/hash/trait.Hasher.html" title="trait core::hash::Hasher"><code>Hasher</code></a>. <a href="https://doc.rust-lang.org/1.78.0/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#78-82">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/1.78.0/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#79-81">source</a><a href="#method.eq" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.78.0/core/cmp/trait.PartialEq.html#tymethod.eq" class="fn">eq</a>(&amp;self, other: <a class="primitive" href="https://doc.rust-lang.org/1.78.0/std/primitive.reference.html">&amp;Self</a>) -&gt; <a class="primitive" href="https://doc.rust-lang.org/1.78.0/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/1.78.0/src/core/cmp.rs.html#263">source</a></span><a href="#method.ne" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.78.0/core/cmp/trait.PartialEq.html#method.ne" class="fn">ne</a>(&amp;self, other: <a class="primitive" href="https://doc.rust-lang.org/1.78.0/std/primitive.reference.html">&amp;Rhs</a>) -&gt; <a class="primitive" href="https://doc.rust-lang.org/1.78.0/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#765-775">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#766-774">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/1.78.0/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#75">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/1.78.0/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-Freeze-for-Attribute" class="impl"><a href="#impl-Freeze-for-Attribute" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.78.0/core/marker/trait.Freeze.html" title="trait core::marker::Freeze">Freeze</a> for <a class="struct" href="struct.Attribute.html" title="struct syn::Attribute">Attribute</a></h3></section><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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/core/borrow/trait.Borrow.html#tymethod.borrow" class="fn">borrow</a>(&amp;self) -&gt; <a class="primitive" href="https://doc.rust-lang.org/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/src/core/convert/mod.rs.html#765">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/1.78.0/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/1.78.0/src/core/convert/mod.rs.html#768">source</a><a href="#method.from" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.78.0/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/1.78.0/src/core/convert/mod.rs.html#748-750">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/1.78.0/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/1.78.0/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/1.78.0/src/core/convert/mod.rs.html#758">source</a><a href="#method.into" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/src/core/convert/mod.rs.html#805-807">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/1.78.0/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/1.78.0/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-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/1.78.0/core/convert/trait.TryFrom.html#associatedtype.Error" class="associatedtype">Error</a> = <a class="enum" href="https://doc.rust-lang.org/1.78.0/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/1.78.0/src/core/convert/mod.rs.html#812">source</a><a href="#method.try_from" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/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/1.78.0/src/core/convert/mod.rs.html#790-792">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/1.78.0/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/1.78.0/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" class="associatedtype trait-impl"><a href="#associatedtype.Error" class="anchor">§</a><h4 class="code-header">type <a href="https://doc.rust-lang.org/1.78.0/core/convert/trait.TryInto.html#associatedtype.Error" class="associatedtype">Error</a> = &lt;U as <a class="trait" href="https://doc.rust-lang.org/1.78.0/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/1.78.0/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/1.78.0/src/core/convert/mod.rs.html#797">source</a><a href="#method.try_into" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.78.0/core/convert/trait.TryInto.html#tymethod.try_into" class="fn">try_into</a>(self) -&gt; <a class="enum" href="https://doc.rust-lang.org/1.78.0/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/1.78.0/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/1.78.0/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>
Reference in a new issue View git blame Copy permalink