<!DOCTYPE html><htmllang="en"><head><metacharset="utf-8"><metaname="viewport"content="width=device-width, initial-scale=1.0"><metaname="generator"content="rustdoc"><metaname="description"content="Types that can be parsed by looking at just one token."><title>Peek in syn::parse - Rust</title><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/SourceSerif4-Regular-46f98efaafac5295.ttf.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/FiraSans-Regular-018c141bf0843ffd.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/FiraSans-Medium-8f9a781e4970d388.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2"><linkrel="preload"as="font"type="font/woff2"crossoriginhref="../../static.files/SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2"><linkrel="stylesheet"href="../../static.files/normalize-76eba96aa4d2e634.css"><linkrel="stylesheet"href="../../static.files/rustdoc-ac92e1bbe349e143.css"><metaname="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"><scriptsrc="../../static.files/storage-f2adc0d6ca4d09fb.js"></script><scriptdefersrc="sidebar-items.js"></script><scriptdefersrc="../../static.files/main-305769736d49e732.js"></script><noscript><linkrel="stylesheet"href="../../static.files/noscript-feafe1bb7466e4bd.css"></noscript><linkrel="alternate icon"type="image/png"href="../../static.files/favicon-16x16-8b506e7a72182f1c.png"><linkrel="alternate icon"type="image/png"href="../../static.files/favicon-32x32-422f7d1d52889060.png"><linkrel="icon"type="image/svg+xml"href="../../static.files/favicon-2c020d218678b618.svg"></head><bodyclass="rustdoc trait"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><navclass="mobile-topbar"><buttonclass="sidebar-menu-toggle">☰</button></nav><navclass="sidebar"><divclass="sidebar-crate"><h2><ahref="../../syn/index.html">syn</a><spanclass="version">2.0.52</span></h2></div><h2class="location"><ahref="#">Peek</a></h2><divclass="sidebar-elems"><section><h3><ahref="#object-safety">Object Safety</a></h3><h3><ahref="#implementors">Implementors</a></h3></section><h2><ahref="index.html">In syn::parse</a></h2></div></nav><divclass="sidebar-resizer"></div>
<main><divclass="width-limiter"><navclass="sub"><formclass="search-form"><span></span><divid="sidebar-button"tabindex="-1"><ahref="../../syn/all.html"title="show sidebar"></a></div><inputclass="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"><divid="help-button"tabindex="-1"><ahref="../../help.html"title="help">?</a></div><divid="settings-menu"tabindex="-1"><ahref="../../settings.html"title="settings"><imgwidth="22"height="22"alt="Change settings"src="../../static.files/wheel-7b819b6101059cd0.svg"></a></div></form></nav><sectionid="main-content"class="content"><divclass="main-heading"><h1>Trait <ahref="../index.html">syn</a>::<wbr><ahref="index.html">parse</a>::<wbr><aclass="trait"href="#">Peek</a><buttonid="copy-path"title="Copy item path to clipboard"><imgsrc="../../static.files/clipboard-7571035ce49a181d.svg"width="19"height="18"alt="Copy item path"></button></h1><spanclass="out-of-band"><aclass="src"href="../../src/syn/lookahead.rs.html#147-151">source</a> · <buttonid="toggle-all-docs"title="collapse all docs">[<span>−</span>]</button></span></div><preclass="rust item-decl"><code>pub trait Peek: Sealed { }</code></pre><detailsclass="toggle top-doc"open><summaryclass="hideme"><span>Expand description</span></summary><divclass="docblock"><p>Types that can be parsed by looking at just one token.</p>
<p>Use <ahref="struct.ParseBuffer.html#method.peek"title="method syn::parse::ParseBuffer::peek"><code>ParseStream::peek</code></a> to peek one of these types in a parse stream
without consuming it from the stream.</p>
<p>This trait is sealed and cannot be implemented for types outside of Syn.</p>
</div></details><h2id="object-safety"class="section-header">Object Safety<ahref="#object-safety"class="anchor">§</a></h2><divclass="object-safety-info">This trait is <b>not</b><ahref="https://doc.rust-lang.org/1.76.0/reference/items/traits.html#object-safety">object safe</a>.</div><h2id="implementors"class="section-header">Implementors<ahref="#implementors"class="anchor">§</a></h2><divid="implementors-list"><sectionid="impl-Peek-for-F"class="impl"><aclass="src rightside"href="../../src/syn/lookahead.rs.html#153-155">source</a><ahref="#impl-Peek-for-F"class="anchor">§</a><h3class="code-header">impl<F: <aclass="trait"href="https://doc.rust-lang.org/1.76.0/core/marker/trait.Copy.html"title="trait core::marker::Copy">Copy</a> + <aclass="trait"href="https://doc.rust-lang.org/1.76.0/core/ops/function/trait.FnOnce.html"title="trait core::ops::function::FnOnce">FnOnce</a>(TokenMarker) -> T, T: <aclass="trait"href="../token/trait.Token.html"title="trait syn::token::Token">Token</a>><aclass="trait"href="trait.Peek.html"title="trait syn::parse::Peek">Peek</a> for F</h3></section></div><scriptsrc="../../trait.impl/syn/lookahead/trait.Peek.js"async></script></section></div></main></body></html>
