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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="A synchronization primitive which can be used to run a one-time initialization. Useful for one-time initialization for globals, FFI or related functionality."><title>Once in parking_lot - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Italic-81dc35de.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-MediumItalic-ccf7e434.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2"href="../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../static.files/rustdoc-ca0dd0c4.css"><meta name="rustdoc-vars" data-root-path="../" data-static-root-path="../static.files/" data-current-crate="parking_lot" data-themes="" data-resource-suffix="" data-rustdoc-version="1.93.1 (01f6ddf75 2026-02-11) (Arch Linux rust 1:1.93.1-1)" data-channel="1.93.1" data-search-js="search-9e2438ea.js" data-stringdex-js="stringdex-a3946164.js" data-settings-js="settings-c38705f0.js" ><script src="../static.files/storage-e2aeef58.js"></script><script defer src="sidebar-items.js"></script><script defer src="../static.files/main-a410ff4d.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-263c88ec.css"></noscript><link rel="alternate icon" type="image/png" href="../static.files/favicon-32x32-eab170b8.png"><link rel="icon" type="image/svg+xml" href="../static.files/favicon-044be391.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]--><rustdoc-topbar><h2><a href="#">Once</a></h2></rustdoc-topbar><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../parking_lot/index.html">parking_<wbr>lot</a><span class="version">0.12.5</span></h2></div><div class="sidebar-elems"><section id="rustdoc-toc"><h2 class="location"><a href="#">Once</a></h2><h3><a href="#">Sections</a></h3><ul class="block top-toc"><li><a href="#differences-from-the-standard-library-once" title="Differences from the standard library `Once`">Differences from the standard library <code>Once</code></a></li><li><a href="#examples" title="Examples">Examples</a></li></ul><h3><a href="#implementations">Methods</a></h3><ul class="block method"><li><a href="#method.call_once" title="call_once">call_once</a></li><li><a href="#method.call_once_force" title="call_once_force">call_once_force</a></li><li><a href="#method.new" title="new">new</a></li><li><a href="#method.state" title="state">state</a></li></ul><h3><a href="#trait-implementations">Trait Implementations</a></h3><ul class="block trait-implementation"><li><a href="#impl-Debug-for-Once" title="Debug">Debug</a></li><li><a href="#impl-Default-for-Once" title="Default">Default</a></li></ul><h3><a href="#synthetic-implementations">Auto Trait Implementations</a></h3><ul class="block synthetic-implementation"><li><a href="#impl-Freeze-for-Once" title="!Freeze">!Freeze</a></li><li><a href="#impl-RefUnwindSafe-for-Once" title="RefUnwindSafe">RefUnwindSafe</a></li><li><a href="#impl-Send-for-Once" title="Send">Send</a></li><li><a href="#impl-Sync-for-Once" title="Sync">Sync</a></li><li><a href="#impl-Unpin-for-Once" title="Unpin">Unpin</a></li><li><a href="#impl-UnwindSafe-for-Once" title="UnwindSafe">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" title="Any">Any</a></li><li><a href="#impl-Borrow%3CT%3E-for-T" title="Borrow&#60;T&#62;">Borrow&#60;T&#62;</a></li><li><a href="#impl-BorrowMut%3CT%3E-for-T" title="BorrowMut&#60;T&#62;">BorrowMut&#60;T&#62;</a></li><li><a href="#impl-From%3CT%3E-for-T" title="From&#60;T&#62;">From&#60;T&#62;</a></li><li><a href="#impl-Into%3CU%3E-for-T" title="Into&#60;U&#62;">Into&#60;U&#62;</a></li><li><a href="#impl-TryFrom%3CU%3E-for-T" title="TryFrom&#60;U&#62;">TryFrom&#60;U&#62;</a></li><li><a href="#impl-TryInto%3CU%3E-for-T" title="TryInto&#60;U&#62;">TryInto&#60;U&#62;</a></li></ul></section><div id="rustdoc-modnav"><h2 class="in-crate"><a href="index.html">In crate parking_<wbr>lot</a></h2></div></div></nav><div class="sidebar-resizer" title="Drag to resize sidebar"></div><main><div class="width-limiter"><section id="main-content" class="content"><div class="main-heading"><div class="rustdoc-breadcrumbs"><a href="index.html">parking_lot</a></div><h1>Struct <span class="struct">Once</span>&nbsp;<button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"><a class="src" href="../src/parking_lot/once.rs.html#77">Source</a> </span></div><pre class="rust item-decl"><code>pub struct Once(<span class="comment">/* private fields */</span>);</code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>A synchronization primitive which can be used to run a one-time
initialization. Useful for one-time initialization for globals, FFI or
related functionality.</p>
<h2 id="differences-from-the-standard-library-once"><a class="doc-anchor" href="#differences-from-the-standard-library-once">§</a>Differences from the standard library <code>Once</code></h2>
<ul>
<li>Only requires 1 byte of space, instead of 1 word.</li>
<li>Not required to be <code>'static</code>.</li>
<li>Relaxed memory barriers in the fast path, which can significantly improve
performance on some architectures.</li>
<li>Efficient handling of micro-contention using adaptive spinning.</li>
</ul>
<h2 id="examples"><a class="doc-anchor" href="#examples">§</a>Examples</h2>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>parking_lot::Once;
<span class="kw">static </span>START: Once = Once::new();
START.call_once(|| {
<span class="comment">// run initialization here
</span>});</code></pre></div></div></details><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-Once" class="impl"><a class="src rightside" href="../src/parking_lot/once.rs.html#79-310">Source</a><a href="#impl-Once" class="anchor">§</a><h3 class="code-header">impl <a class="struct" href="struct.Once.html" title="struct parking_lot::Once">Once</a></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.new" class="method"><a class="src rightside" href="../src/parking_lot/once.rs.html#82-84">Source</a><h4 class="code-header">pub const fn <a href="#method.new" class="fn">new</a>() -&gt; <a class="struct" href="struct.Once.html" title="struct parking_lot::Once">Once</a></h4></section></summary><div class="docblock"><p>Creates a new <code>Once</code> value.</p>
</div></details><details class="toggle method-toggle" open><summary><section id="method.state" class="method"><a class="src rightside" href="../src/parking_lot/once.rs.html#88-99">Source</a><h4 class="code-header">pub fn <a href="#method.state" class="fn">state</a>(&amp;self) -&gt; <a class="enum" href="enum.OnceState.html" title="enum parking_lot::OnceState">OnceState</a></h4></section></summary><div class="docblock"><p>Returns the current state of this <code>Once</code>.</p>
</div></details><details class="toggle method-toggle" open><summary><section id="method.call_once" class="method"><a class="src rightside" href="../src/parking_lot/once.rs.html#151-161">Source</a><h4 class="code-header">pub fn <a href="#method.call_once" class="fn">call_once</a>&lt;F&gt;(&amp;self, f: F)<div class="where">where
F: <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>(),</div></h4></section></summary><div class="docblock"><p>Performs an initialization routine once and only once. The given closure
will be executed if this is the first time <code>call_once</code> has been called,
and otherwise the routine will <em>not</em> be invoked.</p>
<p>This method will block the calling thread if another initialization
routine is currently running.</p>
<p>When this function returns, it is guaranteed that some initialization
has run and completed (it may not be the closure specified). It is also
guaranteed that any memory writes performed by the executed closure can
be reliably observed by other threads at this point (there is a
happens-before relation between the closure and code executing after the
return).</p>
<h5 id="examples-1"><a class="doc-anchor" href="#examples-1">§</a>Examples</h5>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>parking_lot::Once;
<span class="kw">static </span><span class="kw-2">mut </span>VAL: usize = <span class="number">0</span>;
<span class="kw">static </span>INIT: Once = Once::new();
<span class="comment">// Accessing a `static mut` is unsafe much of the time, but if we do so
// in a synchronized fashion (e.g. write once or read all) then we're
// good to go!
//
// This function will only call `expensive_computation` once, and will
// otherwise always return the value returned from the first invocation.
</span><span class="kw">fn </span>get_cached_val() -&gt; usize {
<span class="kw">unsafe </span>{
INIT.call_once(|| {
VAL = expensive_computation();
});
VAL
}
}
<span class="kw">fn </span>expensive_computation() -&gt; usize {
<span class="comment">// ...
</span>}</code></pre></div><h5 id="panics"><a class="doc-anchor" href="#panics">§</a>Panics</h5>
<p>The closure <code>f</code> will only be executed once if this is called
concurrently amongst many threads. If that closure panics, however, then
it will <em>poison</em> this <code>Once</code> instance, causing all future invocations of
<code>call_once</code> to also panic.</p>
</div></details><details class="toggle method-toggle" open><summary><section id="method.call_once_force" class="method"><a class="src rightside" href="../src/parking_lot/once.rs.html#173-185">Source</a><h4 class="code-header">pub fn <a href="#method.call_once_force" class="fn">call_once_force</a>&lt;F&gt;(&amp;self, f: F)<div class="where">where
F: <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>(<a class="enum" href="enum.OnceState.html" title="enum parking_lot::OnceState">OnceState</a>),</div></h4></section></summary><div class="docblock"><p>Performs the same function as <code>call_once</code> except ignores poisoning.</p>
<p>If this <code>Once</code> has been poisoned (some initialization panicked) then
this function will continue to attempt to call initialization functions
until one of them doesnt panic.</p>
<p>The closure <code>f</code> is yielded a structure which can be used to query the
state of this <code>Once</code> (whether initialization has previously panicked or
not).</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-Debug-for-Once" class="impl"><a class="src rightside" href="../src/parking_lot/once.rs.html#319-325">Source</a><a href="#impl-Debug-for-Once" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/fmt/trait.Debug.html" title="trait core::fmt::Debug">Debug</a> for <a class="struct" href="struct.Once.html" title="struct parking_lot::Once">Once</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/parking_lot/once.rs.html#320-324">Source</a><a href="#method.fmt" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/core/fmt/trait.Debug.html#tymethod.fmt" class="fn">fmt</a>(&amp;self, f: &amp;mut <a class="struct" href="https://doc.rust-lang.org/1.93.1/core/fmt/struct.Formatter.html" title="struct core::fmt::Formatter">Formatter</a>&lt;'_&gt;) -&gt; <a class="type" href="https://doc.rust-lang.org/1.93.1/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/1.93.1/core/fmt/trait.Debug.html#tymethod.fmt">Read more</a></div></details></div></details><details class="toggle implementors-toggle" open><summary><section id="impl-Default-for-Once" class="impl"><a class="src rightside" href="../src/parking_lot/once.rs.html#312-317">Source</a><a href="#impl-Default-for-Once" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/default/trait.Default.html" title="trait core::default::Default">Default</a> for <a class="struct" href="struct.Once.html" title="struct parking_lot::Once">Once</a></h3></section></summary><div class="impl-items"><details class="toggle method-toggle" open><summary><section id="method.default" class="method trait-impl"><a class="src rightside" href="../src/parking_lot/once.rs.html#314-316">Source</a><a href="#method.default" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/core/default/trait.Default.html#tymethod.default" class="fn">default</a>() -&gt; <a class="struct" href="struct.Once.html" title="struct parking_lot::Once">Once</a></h4></section></summary><div class='docblock'>Returns the “default value” for a type. <a href="https://doc.rust-lang.org/1.93.1/core/default/trait.Default.html#tymethod.default">Read more</a></div></details></div></details></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-Once" class="impl"><a href="#impl-Freeze-for-Once" class="anchor">§</a><h3 class="code-header">impl !<a class="trait" href="https://doc.rust-lang.org/1.93.1/core/marker/trait.Freeze.html" title="trait core::marker::Freeze">Freeze</a> for <a class="struct" href="struct.Once.html" title="struct parking_lot::Once">Once</a></h3></section><section id="impl-RefUnwindSafe-for-Once" class="impl"><a href="#impl-RefUnwindSafe-for-Once" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/panic/unwind_safe/trait.RefUnwindSafe.html" title="trait core::panic::unwind_safe::RefUnwindSafe">RefUnwindSafe</a> for <a class="struct" href="struct.Once.html" title="struct parking_lot::Once">Once</a></h3></section><section id="impl-Send-for-Once" class="impl"><a href="#impl-Send-for-Once" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a> for <a class="struct" href="struct.Once.html" title="struct parking_lot::Once">Once</a></h3></section><section id="impl-Sync-for-Once" class="impl"><a href="#impl-Sync-for-Once" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/marker/trait.Sync.html" title="trait core::marker::Sync">Sync</a> for <a class="struct" href="struct.Once.html" title="struct parking_lot::Once">Once</a></h3></section><section id="impl-Unpin-for-Once" class="impl"><a href="#impl-Unpin-for-Once" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/marker/trait.Unpin.html" title="trait core::marker::Unpin">Unpin</a> for <a class="struct" href="struct.Once.html" title="struct parking_lot::Once">Once</a></h3></section><section id="impl-UnwindSafe-for-Once" class="impl"><a href="#impl-UnwindSafe-for-Once" class="anchor">§</a><h3 class="code-header">impl <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/panic/unwind_safe/trait.UnwindSafe.html" title="trait core::panic::unwind_safe::UnwindSafe">UnwindSafe</a> for <a class="struct" href="struct.Once.html" title="struct parking_lot::Once">Once</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/1.93.1/src/core/any.rs.html#138">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/1.93.1/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/1.93.1/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/1.93.1/src/core/any.rs.html#139">Source</a><a href="#method.type_id" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/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/1.93.1/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/1.93.1/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/1.93.1/src/core/borrow.rs.html#212">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/1.93.1/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/1.93.1/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/1.93.1/src/core/borrow.rs.html#214">Source</a><a href="#method.borrow" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/core/borrow/trait.Borrow.html#tymethod.borrow" class="fn">borrow</a>(&amp;self) -&gt; <a class="primitive" href="https://doc.rust-lang.org/1.93.1/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/1.93.1/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/1.93.1/src/core/borrow.rs.html#221">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/1.93.1/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/1.93.1/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/1.93.1/src/core/borrow.rs.html#222">Source</a><a href="#method.borrow_mut" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/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/1.93.1/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/1.93.1/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/1.93.1/src/core/convert/mod.rs.html#785">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/1.93.1/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/1.93.1/src/core/convert/mod.rs.html#788">Source</a><a href="#method.from" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/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/1.93.1/src/core/convert/mod.rs.html#767-769">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/1.93.1/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/1.93.1/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/1.93.1/src/core/convert/mod.rs.html#777">Source</a><a href="#method.into" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/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/1.93.1/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-TryFrom%3CU%3E-for-T" class="impl"><a class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/convert/mod.rs.html#827-829">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/1.93.1/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/1.93.1/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 class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/convert/mod.rs.html#831">Source</a><a href="#associatedtype.Error-1" class="anchor">§</a><h4 class="code-header">type <a href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryFrom.html#associatedtype.Error" class="associatedtype">Error</a> = <a class="enum" href="https://doc.rust-lang.org/1.93.1/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/1.93.1/src/core/convert/mod.rs.html#834">Source</a><a href="#method.try_from" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/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/1.93.1/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/1.93.1/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/1.93.1/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/1.93.1/src/core/convert/mod.rs.html#811-813">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/1.93.1/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/1.93.1/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 class="src rightside" href="https://doc.rust-lang.org/1.93.1/src/core/convert/mod.rs.html#815">Source</a><a href="#associatedtype.Error" class="anchor">§</a><h4 class="code-header">type <a href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryInto.html#associatedtype.Error" class="associatedtype">Error</a> = &lt;U as <a class="trait" href="https://doc.rust-lang.org/1.93.1/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/1.93.1/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/1.93.1/src/core/convert/mod.rs.html#818">Source</a><a href="#method.try_into" class="anchor">§</a><h4 class="code-header">fn <a href="https://doc.rust-lang.org/1.93.1/core/convert/trait.TryInto.html#tymethod.try_into" class="fn">try_into</a>(self) -&gt; <a class="enum" href="https://doc.rust-lang.org/1.93.1/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/1.93.1/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/1.93.1/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>