<!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="An error that occurs when Unicode-aware simple case folding fails."><title>CaseFoldError in regex_syntax::hir - 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="regex_syntax"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 struct"><!--[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="../../regex_syntax/index.html">regex_syntax</a><spanclass="version">0.8.2</span></h2></div><h2class="location"><ahref="#">CaseFoldError</a></h2><divclass="sidebar-elems"><section><h3><ahref="#trait-implementations">Trait Implementations</a></h3><ulclass="block trait-implementation"><li><ahref="#impl-Debug-for-CaseFoldError">Debug</a></li><li><ahref="#impl-Display-for-CaseFoldError">Display</a></li><li><ahref="#impl-Error-for-CaseFoldError">Error</a></li></ul><h3><ahref="#synthetic-implementations">Auto Trait Implementations</a></h3><ulclass="block synthetic-implementation"><li><ahref="#impl-RefUnwindSafe-for-CaseFoldError">RefUnwindSafe</a></li><li><ahref="#impl-Send-for-CaseFoldError">Send</a></li><li><ahref="#impl-Sync-for-CaseFoldError">Sync</a></li><li><ahref="#impl-Unpin-for-CaseFoldError">Unpin</a></li><li><ahref="#impl-UnwindSafe-for-CaseFoldError">UnwindSafe</a></li></ul><h3><ahref="#blanket-implementations">Blanket Implementations</a></h3><ulclass="block blanket-implementation"><li><ahref="#impl-Any-for-T">Any</a></li><li><ahref="#impl-Borrow%3CT%3E-for-T">Borrow<T></a></li><li><ahref="#impl-BorrowMut%3CT%3E-for-T">BorrowMut<T></a></li><li><ahref="#impl-From%3CT%3E-for-T">From<T></a></li><li><ahref="#impl-Into%3CU%3E-for-T">Into<U></a></li><li><ahref="#impl-ToString-for-T">ToString</a></li><li><ahref="#impl-TryFrom%3CU%3E-for-T">TryFrom<U></a></li><li><ahref="#impl-TryInto%3CU%3E-for-T">TryInto<U></a></li></ul></section><h2><ahref="index.html">In regex_syntax::hir</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="../../regex_syntax/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>Struct <ahref="../index.html">regex_syntax</a>::<wbr><ahref="index.html">hir</a>::<wbr><aclass="struct"href="#">CaseFoldError</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/regex_syntax/unicode.rs.html#31">source</a> · <buttonid="toggle-all-docs"title="collapse all docs">[<span>−</span>]</button></span></div><preclass="rust item-decl"><code>pub struct CaseFoldError(<spanclass="comment">/* private fields */</span>);</code></pre><detailsclass="toggle top-doc"open><summaryclass="hideme"><span>Expand description</span></summary><divclass="docblock"><p>An error that occurs when Unicode-aware simple case folding fails.</p>
<p>This error can occur when the case mapping tables necessary for Unicode
aware case folding are unavailable. This only occurs when the
<code>unicode-case</code> feature is disabled. (The feature is enabled by default.)</p>
</div></details><h2id="trait-implementations"class="section-header">Trait Implementations<ahref="#trait-implementations"class="anchor">§</a></h2><divid="trait-implementations-list"><detailsclass="toggle implementors-toggle"open><summary><sectionid="impl-Debug-for-CaseFoldError"class="impl"><aclass="src rightside"href="../../src/regex_syntax/unicode.rs.html#30">source</a><ahref="#impl-Debug-for-CaseFoldError"class="anchor">§</a><h3class="code-header">impl <aclass="trait"href="https://doc.rust-lang.org/1.76.0/core/fmt/trait.Debug.html"title="trait core::fmt::Debug">Debug</a> for <aclass="struct"href="struct.CaseFoldError.html"title="struct regex_syntax::hir::CaseFoldError">CaseFoldError</a></h3></section></summary><divclass="impl-items"><detailsclass="toggle method-toggle"open><summary><sectionid="method.fmt"class="method trait-impl"><aclass="src rightside"href="../../src/regex_syntax/unicode.rs.html#30">source</a><ahref="#method.fmt"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.76.0/core/fmt/trait.Debug.html#tymethod.fmt"class="fn">fmt</a>(&self, f: &mut <aclass="struct"href="https://doc.rust-lang.org/1.76.0/core/fmt/struct.Formatter.html"title="struct core::fmt::Formatter">Formatter</a><'_>) -><aclass="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><divclass='docblock'>Formats the value using the given formatter. <ahref="https://doc.rust-lang.org/1.76.0/core/fmt/trait.Debug.html#tymethod.fmt">Read more</a></div></details></div></details><detailsclass="toggle implementors-toggle"open><summary><sectionid="impl-Display-for-CaseFoldError"class="impl"><aclass="src rightside"href="../../src/regex_syntax/unicode.rs.html#36-44">source</a><ahref="#impl-Display-for-CaseFoldError"class="anchor">§</a><h3class="code-header">impl <aclass="trait"href="https://doc.rust-lang.org/1.76.0/core/fmt/trait.Display.html"title="trait core::fmt::Display">Display</a> for <aclass="struct"href="struct.CaseFoldError.html"title="struct regex_syntax::hir::CaseFoldError">CaseFoldError</a></h3></section></summary><divclass="impl-items"><detailsclass="toggle method-toggle"open><summary><sectionid="method.fmt-1"class="method trait-impl"><aclass="src rightside"href="../../src/regex_syntax/unicode.rs.html#37-43">source</a><ahref="#method.fmt-1"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.76.0/core/fmt/trait.Display.html#tymethod.fmt"class="fn">fmt</a>(&self, f: &mut <aclass="struct"href="https://doc.rust-lang.org/1.76.0/core/fmt/struct.Formatter.html"title="struct core::fmt::Formatter">Formatter</a><'_>) -><aclass="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><divclass='docblock'>Formats the value using the given formatter. <ahref="https://doc.rust-lang.org/1.76.0/core/fmt/trait.Display.html#tymethod.fmt">Read more</a></div></details></div></details><detailsclass="toggle implementors-toggle"open><summary><sectionid="impl-Error-for-CaseFoldError"class="impl"><aclass="src rightside"href="../../src/regex_syntax/unicode.rs.html#34">source</a><ahref="#impl-Error-for-CaseFoldError"class="anchor">§</a><h3class="code-header">impl <aclass="trait"href="https://doc.rust-lang.org/1.76.0/core/error/trait.Error.html"title="trait core::error::Error">Error</a> for <aclass="struct"href="struct.CaseFoldError.html"title="struct regex_syntax::hir::CaseFoldError">CaseFoldError</a></h3></section></summary><divclass="impl-items"><detailsclass="toggle method-toggle"open><summary><sectionid="method.source"class="method trait-impl"><spanclass="rightside"><spanclass="since"title="Stable since Rust version 1.30.0">1.30.0</span> · <aclass="src"href="https://doc.rust-lang.org/1.76.0/src/core/error.rs.html#84">source</a></span><ahref="#method.source"class="anchor">§</a><h4class="code-header">fn
<p>That is, this conversion is whatever the implementation of
<code><ahref="https://doc.rust-lang.org/1.76.0/core/convert/trait.From.html"title="trait core::convert::From">From</a><T> for U</code> chooses to do.</p>
</div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-ToString-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.76.0/src/alloc/string.rs.html#2600">source</a><ahref="#impl-ToString-for-T"class="anchor">§</a><h3class="code-header">impl<T><aclass="trait"href="https://doc.rust-lang.org/1.76.0/alloc/string/trait.ToString.html"title="trait alloc::string::ToString">ToString</a> for T<divclass="where">where
T: <aclass="trait"href="https://doc.rust-lang.org/1.76.0/core/fmt/trait.Display.html"title="trait core::fmt::Display">Display</a> + ?<aclass="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><divclass="impl-items"><detailsclass="toggle method-toggle"open><summary><sectionid="method.to_string"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.76.0/src/alloc/string.rs.html#2606">source</a><ahref="#method.to_string"class="anchor">§</a><h4class="code-header">default fn <ahref="https://doc.rust-lang.org/1.76.0/alloc/string/trait.ToString.html#tymethod.to_string"class="fn">to_string</a>(&self) -><aclass="struct"href="https://doc.rust-lang.org/1.76.0/alloc/string/struct.String.html"title="struct alloc::string::String">String</a></h4></section></summary><divclass='docblock'>Converts the given value to a <code>String</code>. <ahref="https://doc.rust-lang.org/1.76.0/alloc/string/trait.ToString.html#tymethod.to_string">Read more</a></div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-TryFrom%3CU%3E-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.76.0/src/core/convert/mod.rs.html#803-805">source</a><ahref="#impl-TryFrom%3CU%3E-for-T"class="anchor">§</a><h3class="code-header">impl<T, U><aclass="trait"href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><U> for T<divclass="where">where
U: <aclass="trait"href="https://doc.rust-lang.org/1.76.0/core/convert/trait.Into.html"title="trait core::convert::Into">Into</a><T>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle"open><summary><sectionid="associatedtype.Error"class="associatedtype trait-impl"><ahref="#associatedtype.Error"class="anchor">§</a><h4class="code-header">type <ahref="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html#associatedtype.Error"class="associatedtype">Error</a> = <aclass="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><divclass='docblock'>The type returned in the event of a conversion error.</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.try_from"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.76.0/src/core/convert/mod.rs.html#810">source</a><ahref="#method.try_from"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html#tymethod.try_from"class="fn">try_from</a>(value: U) -><aclass="enum"href="https://doc.rust-lang.org/1.76.0/core/result/enum.Result.html"title="enum core::result::Result">Result</a><T, <T as <aclass="trait"href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><U>>::<aclass="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><divclass='docblock'>Performs the conversion.</div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-TryInto%3CU%3E-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.76.0/src/core/convert/mod.rs.html#788-790">source</a><ahref="#impl-TryInto%3CU%3E-for-T"class="anchor">§</a><h3class="code-header">impl<T, U><aclass="trait"href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryInto.html"title="trait core::convert::TryInto">TryInto</a><U> for T<divclass="where">where
U: <aclass="trait"href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle"open><summary><sectionid="associatedtype.Error-1"class="associatedtype trait-impl"><ahref="#associatedtype.Error-1"class="anchor">§</a><h4class="code-header">type <ahref="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryInto.html#associatedtype.Error"class="associatedtype">Error</a> = <U as <aclass="trait"href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>>::<aclass="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><divclass='docblock'>The type returned in the event of a conversion error.</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.try_into"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.76.0/src/core/convert/mod.rs.html#795">source</a><ahref="#method.try_into"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryInto.html#tymethod.try_into"class="fn">try_into</a>(self) -><aclass="enum"href="https://doc.rust-lang.org/1.76.0/core/result/enum.Result.html"title="enum core::result::Result">Result</a><U, <U as <aclass="trait"href="https://doc.rust-lang.org/1.76.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>>::<aclass="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><divclass='docblock'>Performs the conversion.</div></details></div></details></div></section></div></main></body></html>