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139 lines
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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 global initialization. Useful for one-time initialization for FFI or related functionality. This type can only be constructed with [`Once::new()`]."><meta name="keywords" content="rust, rustlang, rust-lang, Once"><title>Once in tracing_core - Rust</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" type="text/css" href="../normalize.css"><link rel="stylesheet" type="text/css" href="../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../ayu.css" disabled><link rel="stylesheet" type="text/css" href="../dark.css" disabled><link rel="stylesheet" type="text/css" href="../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../storage.js"></script><script src="../crates.js"></script><script defer src="../main.js"></script>
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</a><h2 class="location">Struct Once</h2><div class="sidebar-elems"><div class="block items"><h3 class="sidebar-title"><a href="#implementations">Methods</a></h3><div class="sidebar-links"><a href="#method.call_once">call_once</a><a href="#method.call_once_force">call_once_force</a><a href="#method.is_completed">is_completed</a><a href="#method.new">new</a></div><h3 class="sidebar-title"><a href="#trait-implementations">Trait Implementations</a></h3><div class="sidebar-links"><a href="#impl-Debug">Debug</a><a href="#impl-RefUnwindSafe">RefUnwindSafe</a><a href="#impl-Send">Send</a><a href="#impl-Sync">Sync</a><a href="#impl-UnwindSafe">UnwindSafe</a></div><h3 class="sidebar-title"><a href="#synthetic-implementations">Auto Trait Implementations</a></h3><div class="sidebar-links"><a href="#impl-Unpin">Unpin</a></div><h3 class="sidebar-title"><a href="#blanket-implementations">Blanket Implementations</a></h3><div class="sidebar-links"><a href="#impl-Any">Any</a><a href="#impl-Borrow%3CT%3E">Borrow<T></a><a href="#impl-BorrowMut%3CT%3E">BorrowMut<T></a><a href="#impl-From%3CT%3E">From<T></a><a href="#impl-Into%3CU%3E">Into<U></a><a href="#impl-TryFrom%3CU%3E">TryFrom<U></a><a href="#impl-TryInto%3CU%3E">TryInto<U></a></div></div><h2 class="location">Other items in<br><a href="index.html">tracing_core</a></h2><div id="sidebar-vars" data-name="Once" data-ty="struct" data-relpath=""></div><script defer src="sidebar-items.js"></script></div></nav><main><div class="width-limiter"><div class="sub-container"><a class="sub-logo-container" href="../tracing_core/index.html"><img src="https://raw.githubusercontent.com/tokio-rs/tracing/master/assets/logo-type.png" alt="logo"></a><nav class="sub"><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!" aria-haspopup="menu" title="themes"><img width="18" height="18" alt="Pick another theme!" src="../brush.svg"></button><div id="theme-choices" role="menu"></div></div><form class="search-form"><div class="search-container"><div><select id="crate-search"><option value="All crates">All crates</option></select><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"></div><button type="button" id="help-button" title="help">?</button><a id="settings-menu" href="../settings.html" title="settings"><img width="18" height="18" alt="Change settings" src="../wheel.svg"></a></div></form></nav></div><section id="main-content" class="content"><h1 class="fqn"><span class="in-band">Struct <a href="index.html">tracing_core</a>::<wbr><a class="struct" href="#">Once</a><button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"><img src="../clipboard.svg" width="19" height="18" alt="Copy item path"></button></span><span class="out-of-band"><span class="since" title="Stable since Rust version 1.0.0">1.0.0</span><span id="render-detail"><a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/std/sync/once.rs.html#113-118" title="goto source code">[src]</a></span></h1><div class="docblock item-decl"><pre class="rust struct"><code>pub struct Once { /* fields omitted */ }</code></pre></div><details class="rustdoc-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 global
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initialization. Useful for one-time initialization for FFI or related
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functionality. This type can only be constructed with <a href="struct.Once.html#method.new" title="Once::new()"><code>Once::new()</code></a>.</p>
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<h2 id="examples" class="section-header"><a href="#examples">Examples</a></h2>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use</span> <span class="ident">std::sync::Once</span>;
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<span class="kw">static</span> <span class="ident">START</span>: <span class="ident">Once</span> <span class="op">=</span> <span class="ident">Once::new</span>();
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<span class="ident">START</span>.<span class="ident">call_once</span>(<span class="op">|</span><span class="op">|</span> {
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<span class="comment">// run initialization here</span>
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});</code></pre></div>
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</div></details><h2 id="implementations" class="small-section-header">Implementations<a href="#implementations" class="anchor"></a></h2><details class="rustdoc-toggle implementors-toggle" open><summary><div id="impl" class="impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/std/sync/once.rs.html#191-440" title="goto source code">[src]</a></div><a href="#impl" class="anchor"></a><h3 class="code-header in-band">impl <a class="struct" href="struct.Once.html" title="struct tracing_core::Once">Once</a></h3></div></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><div id="method.new" class="method has-srclink"><div class="rightside"><span class="since" title="Stable since Rust version 1.2.0, const since 1.32.0">1.2.0 (const: 1.32.0)</span><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/std/sync/once.rs.html#197" title="goto source code">[src]</a></div><a href="#method.new" class="anchor"></a><h4 class="code-header">pub const fn <a href="#method.new" class="fnname">new</a>() -> <a class="struct" href="struct.Once.html" title="struct tracing_core::Once">Once</a></h4></div></summary><div class="docblock"><p>Creates a new <code>Once</code> value.</p>
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</div></details><details class="rustdoc-toggle method-toggle" open><summary><div id="method.call_once" class="method has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/std/sync/once.rs.html#259-261" title="goto source code">[src]</a></div><a href="#method.call_once" class="anchor"></a><h4 class="code-header">pub fn <a href="#method.call_once" class="fnname">call_once</a><F>(&self, f: F) <span class="where fmt-newline">where<br> F: <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>(), </span></h4></div></summary><div class="docblock"><p>Performs an initialization routine once and only once. The given closure
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will be executed if this is the first time <code>call_once</code> has been called,
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and otherwise the routine will <em>not</em> be invoked.</p>
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<p>This method will block the calling thread if another initialization
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routine is currently running.</p>
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<p>When this function returns, it is guaranteed that some initialization
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has run and completed (it might not be the closure specified). It is also
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guaranteed that any memory writes performed by the executed closure can
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be reliably observed by other threads at this point (there is a
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happens-before relation between the closure and code executing after the
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return).</p>
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<p>If the given closure recursively invokes <code>call_once</code> on the same <a href="struct.Once.html" title="Once"><code>Once</code></a>
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instance the exact behavior is not specified, allowed outcomes are
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a panic or a deadlock.</p>
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<h5 id="examples-1" class="section-header"><a href="#examples-1">Examples</a></h5>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use</span> <span class="ident">std::sync::Once</span>;
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<span class="kw">static</span> <span class="kw-2">mut</span> <span class="ident">VAL</span>: <span class="ident">usize</span> <span class="op">=</span> <span class="number">0</span>;
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<span class="kw">static</span> <span class="ident">INIT</span>: <span class="ident">Once</span> <span class="op">=</span> <span class="ident">Once::new</span>();
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<span class="comment">// Accessing a `static mut` is unsafe much of the time, but if we do so</span>
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<span class="comment">// in a synchronized fashion (e.g., write once or read all) then we're</span>
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<span class="comment">// good to go!</span>
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<span class="comment">//</span>
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<span class="comment">// This function will only call `expensive_computation` once, and will</span>
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<span class="comment">// otherwise always return the value returned from the first invocation.</span>
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<span class="kw">fn</span> <span class="ident">get_cached_val</span>() -> <span class="ident">usize</span> {
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<span class="kw">unsafe</span> {
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<span class="ident">INIT</span>.<span class="ident">call_once</span>(<span class="op">|</span><span class="op">|</span> {
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<span class="ident">VAL</span> <span class="op">=</span> <span class="ident">expensive_computation</span>();
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});
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<span class="ident">VAL</span>
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}
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}
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<span class="kw">fn</span> <span class="ident">expensive_computation</span>() -> <span class="ident">usize</span> {
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<span class="comment">// ...</span>
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}</code></pre></div>
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<h5 id="panics" class="section-header"><a href="#panics">Panics</a></h5>
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<p>The closure <code>f</code> will only be executed once if this is called
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concurrently amongst many threads. If that closure panics, however, then
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it will <em>poison</em> this <a href="struct.Once.html" title="Once"><code>Once</code></a> instance, causing all future invocations of
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<code>call_once</code> to also panic.</p>
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<p>This is similar to <a href="struct.Mutex.html#poisoning">poisoning with mutexes</a>.</p>
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</div></details><details class="rustdoc-toggle method-toggle" open><summary><div id="method.call_once_force" class="method has-srclink"><div class="rightside"><span class="since" title="Stable since Rust version 1.51.0">1.51.0</span><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/std/sync/once.rs.html#317-319" title="goto source code">[src]</a></div><a href="#method.call_once_force" class="anchor"></a><h4 class="code-header">pub fn <a href="#method.call_once_force" class="fnname">call_once_force</a><F>(&self, f: F) <span class="where fmt-newline">where<br> F: <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>(&<a class="struct" href="https://doc.rust-lang.org/1.59.0/std/sync/once/struct.OnceState.html" title="struct std::sync::once::OnceState">OnceState</a>), </span></h4></div></summary><div class="docblock"><p>Performs the same function as <a href="struct.Once.html#method.call_once"><code>call_once()</code></a> except ignores poisoning.</p>
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<p>Unlike <a href="struct.Once.html#method.call_once"><code>call_once()</code></a>, if this <a href="struct.Once.html" title="Once"><code>Once</code></a> has been poisoned (i.e., a previous
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call to <a href="struct.Once.html#method.call_once"><code>call_once()</code></a> or <a href="struct.Once.html#method.call_once_force"><code>call_once_force()</code></a> caused a panic), calling
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<a href="struct.Once.html#method.call_once_force"><code>call_once_force()</code></a> will still invoke the closure <code>f</code> and will <em>not</em>
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result in an immediate panic. If <code>f</code> panics, the <a href="struct.Once.html" title="Once"><code>Once</code></a> will remain
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in a poison state. If <code>f</code> does <em>not</em> panic, the <a href="struct.Once.html" title="Once"><code>Once</code></a> will no
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longer be in a poison state and all future calls to <a href="struct.Once.html#method.call_once"><code>call_once()</code></a> or
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<a href="struct.Once.html#method.call_once_force"><code>call_once_force()</code></a> will be no-ops.</p>
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<p>The closure <code>f</code> is yielded a <a href="https://doc.rust-lang.org/1.59.0/std/sync/once/struct.OnceState.html" title="OnceState"><code>OnceState</code></a> structure which can be used
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to query the poison status of the <a href="struct.Once.html" title="Once"><code>Once</code></a>.</p>
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<h5 id="examples-2" class="section-header"><a href="#examples-2">Examples</a></h5>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use</span> <span class="ident">std::sync::Once</span>;
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<span class="kw">use</span> <span class="ident">std::thread</span>;
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<span class="kw">static</span> <span class="ident">INIT</span>: <span class="ident">Once</span> <span class="op">=</span> <span class="ident">Once::new</span>();
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<span class="comment">// poison the once</span>
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<span class="kw">let</span> <span class="ident">handle</span> <span class="op">=</span> <span class="ident">thread::spawn</span>(<span class="op">|</span><span class="op">|</span> {
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<span class="ident">INIT</span>.<span class="ident">call_once</span>(<span class="op">|</span><span class="op">|</span> <span class="macro">panic!</span>());
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});
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<span class="macro">assert!</span>(<span class="ident">handle</span>.<span class="ident">join</span>().<span class="ident">is_err</span>());
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<span class="comment">// poisoning propagates</span>
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<span class="kw">let</span> <span class="ident">handle</span> <span class="op">=</span> <span class="ident">thread::spawn</span>(<span class="op">|</span><span class="op">|</span> {
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<span class="ident">INIT</span>.<span class="ident">call_once</span>(<span class="op">|</span><span class="op">|</span> {});
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});
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<span class="macro">assert!</span>(<span class="ident">handle</span>.<span class="ident">join</span>().<span class="ident">is_err</span>());
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<span class="comment">// call_once_force will still run and reset the poisoned state</span>
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<span class="ident">INIT</span>.<span class="ident">call_once_force</span>(<span class="op">|</span><span class="ident">state</span><span class="op">|</span> {
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<span class="macro">assert!</span>(<span class="ident">state</span>.<span class="ident">is_poisoned</span>());
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});
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<span class="comment">// once any success happens, we stop propagating the poison</span>
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<span class="ident">INIT</span>.<span class="ident">call_once</span>(<span class="op">|</span><span class="op">|</span> {});</code></pre></div>
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</div></details><details class="rustdoc-toggle method-toggle" open><summary><div id="method.is_completed" class="method has-srclink"><div class="rightside"><span class="since" title="Stable since Rust version 1.43.0">1.43.0</span><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/std/sync/once.rs.html#373" title="goto source code">[src]</a></div><a href="#method.is_completed" class="anchor"></a><h4 class="code-header">pub fn <a href="#method.is_completed" class="fnname">is_completed</a>(&self) -> <a class="primitive" href="https://doc.rust-lang.org/1.59.0/std/primitive.bool.html">bool</a></h4></div></summary><div class="docblock"><p>Returns <code>true</code> if some <a href="struct.Once.html#method.call_once"><code>call_once()</code></a> call has completed
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successfully. Specifically, <code>is_completed</code> will return false in
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the following situations:</p>
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<ul>
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<li><a href="struct.Once.html#method.call_once"><code>call_once()</code></a> was not called at all,</li>
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<li><a href="struct.Once.html#method.call_once"><code>call_once()</code></a> was called, but has not yet completed,</li>
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<li>the <a href="struct.Once.html" title="Once"><code>Once</code></a> instance is poisoned</li>
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</ul>
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<p>This function returning <code>false</code> does not mean that <a href="struct.Once.html" title="Once"><code>Once</code></a> has not been
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executed. For example, it may have been executed in the time between
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when <code>is_completed</code> starts executing and when it returns, in which case
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the <code>false</code> return value would be stale (but still permissible).</p>
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<h5 id="examples-3" class="section-header"><a href="#examples-3">Examples</a></h5>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use</span> <span class="ident">std::sync::Once</span>;
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<span class="kw">static</span> <span class="ident">INIT</span>: <span class="ident">Once</span> <span class="op">=</span> <span class="ident">Once::new</span>();
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<span class="macro">assert_eq!</span>(<span class="ident">INIT</span>.<span class="ident">is_completed</span>(), <span class="bool-val">false</span>);
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<span class="ident">INIT</span>.<span class="ident">call_once</span>(<span class="op">|</span><span class="op">|</span> {
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<span class="macro">assert_eq!</span>(<span class="ident">INIT</span>.<span class="ident">is_completed</span>(), <span class="bool-val">false</span>);
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});
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<span class="macro">assert_eq!</span>(<span class="ident">INIT</span>.<span class="ident">is_completed</span>(), <span class="bool-val">true</span>);</code></pre></div>
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<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use</span> <span class="ident">std::sync::Once</span>;
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<span class="kw">use</span> <span class="ident">std::thread</span>;
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<span class="kw">static</span> <span class="ident">INIT</span>: <span class="ident">Once</span> <span class="op">=</span> <span class="ident">Once::new</span>();
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<span class="macro">assert_eq!</span>(<span class="ident">INIT</span>.<span class="ident">is_completed</span>(), <span class="bool-val">false</span>);
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<span class="kw">let</span> <span class="ident">handle</span> <span class="op">=</span> <span class="ident">thread::spawn</span>(<span class="op">|</span><span class="op">|</span> {
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<span class="ident">INIT</span>.<span class="ident">call_once</span>(<span class="op">|</span><span class="op">|</span> <span class="macro">panic!</span>());
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});
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<span class="macro">assert!</span>(<span class="ident">handle</span>.<span class="ident">join</span>().<span class="ident">is_err</span>());
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<span class="macro">assert_eq!</span>(<span class="ident">INIT</span>.<span class="ident">is_completed</span>(), <span class="bool-val">false</span>);</code></pre></div>
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</div></details></div></details><h2 id="trait-implementations" class="small-section-header">Trait Implementations<a href="#trait-implementations" class="anchor"></a></h2><div id="trait-implementations-list"><details class="rustdoc-toggle implementors-toggle" open><summary><div id="impl-Debug" class="impl has-srclink"><div class="rightside"><span class="since" title="Stable since Rust version 1.16.0">1.16.0</span><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/std/sync/once.rs.html#490-494" title="goto source code">[src]</a></div><a href="#impl-Debug" class="anchor"></a><h3 class="code-header in-band">impl <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/fmt/trait.Debug.html" title="trait core::fmt::Debug">Debug</a> for <a class="struct" href="struct.Once.html" title="struct tracing_core::Once">Once</a></h3></div></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><div id="method.fmt" class="method trait-impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/std/sync/once.rs.html#491" title="goto source code">[src]</a></div><a href="#method.fmt" class="anchor"></a><h4 class="code-header">pub fn <a href="https://doc.rust-lang.org/1.59.0/core/fmt/trait.Debug.html#tymethod.fmt" class="fnname">fmt</a>(&self, f: &mut <a class="struct" href="https://doc.rust-lang.org/1.59.0/core/fmt/struct.Formatter.html" title="struct core::fmt::Formatter">Formatter</a><'_>) -> <a class="enum" href="https://doc.rust-lang.org/1.59.0/core/result/enum.Result.html" title="enum core::result::Result">Result</a><<a class="primitive" href="https://doc.rust-lang.org/1.59.0/std/primitive.unit.html">()</a>, <a class="struct" href="https://doc.rust-lang.org/1.59.0/core/fmt/struct.Error.html" title="struct core::fmt::Error">Error</a>></h4></div></summary><div class='docblock'><p>Formats the value using the given formatter. <a href="https://doc.rust-lang.org/1.59.0/core/fmt/trait.Debug.html#tymethod.fmt">Read more</a></p>
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</div></details></div></details><div id="impl-RefUnwindSafe" class="impl has-srclink"><div class="rightside"><span class="since" title="Stable since Rust version 1.59.0">1.59.0</span><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/std/sync/once.rs.html#131" title="goto source code">[src]</a></div><a href="#impl-RefUnwindSafe" class="anchor"></a><h3 class="code-header in-band">impl <a class="trait" href="https://doc.rust-lang.org/1.59.0/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 tracing_core::Once">Once</a></h3></div><div id="impl-Send" class="impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/std/sync/once.rs.html#125" title="goto source code">[src]</a></div><a href="#impl-Send" class="anchor"></a><h3 class="code-header in-band">impl <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a> for <a class="struct" href="struct.Once.html" title="struct tracing_core::Once">Once</a></h3></div><div id="impl-Sync" class="impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/std/sync/once.rs.html#123" title="goto source code">[src]</a></div><a href="#impl-Sync" class="anchor"></a><h3 class="code-header in-band">impl <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/marker/trait.Sync.html" title="trait core::marker::Sync">Sync</a> for <a class="struct" href="struct.Once.html" title="struct tracing_core::Once">Once</a></h3></div><div id="impl-UnwindSafe" class="impl has-srclink"><div class="rightside"><span class="since" title="Stable since Rust version 1.59.0">1.59.0</span><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/std/sync/once.rs.html#128" title="goto source code">[src]</a></div><a href="#impl-UnwindSafe" class="anchor"></a><h3 class="code-header in-band">impl <a class="trait" href="https://doc.rust-lang.org/1.59.0/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 tracing_core::Once">Once</a></h3></div></div><h2 id="synthetic-implementations" class="small-section-header">Auto Trait Implementations<a href="#synthetic-implementations" class="anchor"></a></h2><div id="synthetic-implementations-list"><div id="impl-Unpin" class="impl has-srclink"><div class="rightside"></div><a href="#impl-Unpin" class="anchor"></a><h3 class="code-header in-band">impl <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/marker/trait.Unpin.html" title="trait core::marker::Unpin">Unpin</a> for <a class="struct" href="struct.Once.html" title="struct tracing_core::Once">Once</a></h3></div></div><h2 id="blanket-implementations" class="small-section-header">Blanket Implementations<a href="#blanket-implementations" class="anchor"></a></h2><div id="blanket-implementations-list"><details class="rustdoc-toggle implementors-toggle" open><summary><div id="impl-Any" class="impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/core/any.rs.html#132-136" title="goto source code">[src]</a></div><a href="#impl-Any" class="anchor"></a><h3 class="code-header in-band">impl<T> <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/any/trait.Any.html" title="trait core::any::Any">Any</a> for T <span class="where fmt-newline">where<br> T: 'static + ?<a class="trait" href="https://doc.rust-lang.org/1.59.0/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>, </span></h3></div></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><div id="method.type_id" class="method trait-impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/core/any.rs.html#133" title="goto source code">[src]</a></div><a href="#method.type_id" class="anchor"></a><h4 class="code-header">pub fn <a href="https://doc.rust-lang.org/1.59.0/core/any/trait.Any.html#tymethod.type_id" class="fnname">type_id</a>(&self) -> <a class="struct" href="https://doc.rust-lang.org/1.59.0/core/any/struct.TypeId.html" title="struct core::any::TypeId">TypeId</a></h4></div></summary><div class='docblock'><p>Gets the <code>TypeId</code> of <code>self</code>. <a href="https://doc.rust-lang.org/1.59.0/core/any/trait.Any.html#tymethod.type_id">Read more</a></p>
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</div></details></div></details><details class="rustdoc-toggle implementors-toggle" open><summary><div id="impl-Borrow%3CT%3E" class="impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/core/borrow.rs.html#209-214" title="goto source code">[src]</a></div><a href="#impl-Borrow%3CT%3E" class="anchor"></a><h3 class="code-header in-band">impl<T> <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/borrow/trait.Borrow.html" title="trait core::borrow::Borrow">Borrow</a><T> for T <span class="where fmt-newline">where<br> T: ?<a class="trait" href="https://doc.rust-lang.org/1.59.0/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>, </span></h3></div></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><div id="method.borrow" class="method trait-impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/core/borrow.rs.html#211" title="goto source code">[src]</a></div><a href="#method.borrow" class="anchor"></a><h4 class="code-header">pub fn <a href="https://doc.rust-lang.org/1.59.0/core/borrow/trait.Borrow.html#tymethod.borrow" class="fnname">borrow</a>(&self) -> <a class="primitive" href="https://doc.rust-lang.org/1.59.0/std/primitive.reference.html">&</a>T</h4></div></summary><div class='docblock'><p>Immutably borrows from an owned value. <a href="https://doc.rust-lang.org/1.59.0/core/borrow/trait.Borrow.html#tymethod.borrow">Read more</a></p>
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</div></details></div></details><details class="rustdoc-toggle implementors-toggle" open><summary><div id="impl-BorrowMut%3CT%3E" class="impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/core/borrow.rs.html#218-222" title="goto source code">[src]</a></div><a href="#impl-BorrowMut%3CT%3E" class="anchor"></a><h3 class="code-header in-band">impl<T> <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/borrow/trait.BorrowMut.html" title="trait core::borrow::BorrowMut">BorrowMut</a><T> for T <span class="where fmt-newline">where<br> T: ?<a class="trait" href="https://doc.rust-lang.org/1.59.0/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>, </span></h3></div></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><div id="method.borrow_mut" class="method trait-impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/core/borrow.rs.html#219" title="goto source code">[src]</a></div><a href="#method.borrow_mut" class="anchor"></a><h4 class="code-header">pub fn <a href="https://doc.rust-lang.org/1.59.0/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut" class="fnname">borrow_mut</a>(&mut self) -> <a class="primitive" href="https://doc.rust-lang.org/1.59.0/std/primitive.reference.html">&mut </a>T</h4></div></summary><div class='docblock'><p>Mutably borrows from an owned value. <a href="https://doc.rust-lang.org/1.59.0/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut">Read more</a></p>
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</div></details></div></details><details class="rustdoc-toggle implementors-toggle" open><summary><div id="impl-From%3CT%3E" class="impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/core/convert/mod.rs.html#550-554" title="goto source code">[src]</a></div><a href="#impl-From%3CT%3E" class="anchor"></a><h3 class="code-header in-band">impl<T> <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/convert/trait.From.html" title="trait core::convert::From">From</a><T> for T</h3></div></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><div id="method.from" class="method trait-impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/core/convert/mod.rs.html#551" title="goto source code">[src]</a></div><a href="#method.from" class="anchor"></a><h4 class="code-header">pub fn <a href="https://doc.rust-lang.org/1.59.0/core/convert/trait.From.html#tymethod.from" class="fnname">from</a>(t: T) -> T</h4></div></summary><div class='docblock'><p>Performs the conversion.</p>
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</div></details></div></details><details class="rustdoc-toggle implementors-toggle" open><summary><div id="impl-Into%3CU%3E" class="impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/core/convert/mod.rs.html#538-545" title="goto source code">[src]</a></div><a href="#impl-Into%3CU%3E" class="anchor"></a><h3 class="code-header in-band">impl<T, U> <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/convert/trait.Into.html" title="trait core::convert::Into">Into</a><U> for T <span class="where fmt-newline">where<br> U: <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/convert/trait.From.html" title="trait core::convert::From">From</a><T>, </span></h3></div></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><div id="method.into" class="method trait-impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/core/convert/mod.rs.html#542" title="goto source code">[src]</a></div><a href="#method.into" class="anchor"></a><h4 class="code-header">pub fn <a href="https://doc.rust-lang.org/1.59.0/core/convert/trait.Into.html#tymethod.into" class="fnname">into</a>(self) -> U</h4></div></summary><div class='docblock'><p>Performs the conversion.</p>
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</div></details></div></details><details class="rustdoc-toggle implementors-toggle" open><summary><div id="impl-TryFrom%3CU%3E" class="impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/core/convert/mod.rs.html#588-597" title="goto source code">[src]</a></div><a href="#impl-TryFrom%3CU%3E" class="anchor"></a><h3 class="code-header in-band">impl<T, U> <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><U> for T <span class="where fmt-newline">where<br> U: <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/convert/trait.Into.html" title="trait core::convert::Into">Into</a><T>, </span></h3></div></summary><div class="impl-items"><details class="rustdoc-toggle" open><summary><div id="associatedtype.Error-1" class="type trait-impl has-srclink"><a href="#associatedtype.Error-1" class="anchor"></a><h4 class="code-header">type <a href="https://doc.rust-lang.org/1.59.0/core/convert/trait.TryFrom.html#associatedtype.Error" class="associatedtype">Error</a> = <a class="enum" href="https://doc.rust-lang.org/1.59.0/core/convert/enum.Infallible.html" title="enum core::convert::Infallible">Infallible</a></h4></div></summary><div class='docblock'><p>The type returned in the event of a conversion error.</p>
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</div></details><details class="rustdoc-toggle method-toggle" open><summary><div id="method.try_from" class="method trait-impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/core/convert/mod.rs.html#594" title="goto source code">[src]</a></div><a href="#method.try_from" class="anchor"></a><h4 class="code-header">pub fn <a href="https://doc.rust-lang.org/1.59.0/core/convert/trait.TryFrom.html#tymethod.try_from" class="fnname">try_from</a>(value: U) -> <a class="enum" href="https://doc.rust-lang.org/1.59.0/core/result/enum.Result.html" title="enum core::result::Result">Result</a><T, <T as <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><U>>::<a class="associatedtype" href="https://doc.rust-lang.org/1.59.0/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a>></h4></div></summary><div class='docblock'><p>Performs the conversion.</p>
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</div></details></div></details><details class="rustdoc-toggle implementors-toggle" open><summary><div id="impl-TryInto%3CU%3E" class="impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/core/convert/mod.rs.html#574-583" title="goto source code">[src]</a></div><a href="#impl-TryInto%3CU%3E" class="anchor"></a><h3 class="code-header in-band">impl<T, U> <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/convert/trait.TryInto.html" title="trait core::convert::TryInto">TryInto</a><U> for T <span class="where fmt-newline">where<br> U: <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><T>, </span></h3></div></summary><div class="impl-items"><details class="rustdoc-toggle" open><summary><div id="associatedtype.Error" class="type trait-impl has-srclink"><a href="#associatedtype.Error" class="anchor"></a><h4 class="code-header">type <a href="https://doc.rust-lang.org/1.59.0/core/convert/trait.TryInto.html#associatedtype.Error" class="associatedtype">Error</a> = <U as <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><T>>::<a class="associatedtype" href="https://doc.rust-lang.org/1.59.0/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a></h4></div></summary><div class='docblock'><p>The type returned in the event of a conversion error.</p>
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</div></details><details class="rustdoc-toggle method-toggle" open><summary><div id="method.try_into" class="method trait-impl has-srclink"><div class="rightside"><a class="srclink" href="https://doc.rust-lang.org/1.59.0/src/core/convert/mod.rs.html#580" title="goto source code">[src]</a></div><a href="#method.try_into" class="anchor"></a><h4 class="code-header">pub fn <a href="https://doc.rust-lang.org/1.59.0/core/convert/trait.TryInto.html#tymethod.try_into" class="fnname">try_into</a>(self) -> <a class="enum" href="https://doc.rust-lang.org/1.59.0/core/result/enum.Result.html" title="enum core::result::Result">Result</a><U, <U as <a class="trait" href="https://doc.rust-lang.org/1.59.0/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><T>>::<a class="associatedtype" href="https://doc.rust-lang.org/1.59.0/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a>></h4></div></summary><div class='docblock'><p>Performs the conversion.</p>
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