| <!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="Performs exponential backoff in spin loops."><meta name="keywords" content="rust, rustlang, rust-lang, Backoff"><title>Backoff in crossbeam_utils - 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" 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class="logo-container"><img class="rust-logo" src="../rust-logo.svg" alt="logo"></div></a><h2></h2></nav><nav class="sidebar"><a class="sidebar-logo" href="../crossbeam_utils/index.html"><div class="logo-container"><img class="rust-logo" src="../rust-logo.svg" alt="logo"></div></a><h2 class="location"><a href="#">Backoff</a></h2><div class="sidebar-elems"><section><h3><a href="#implementations">Methods</a></h3><ul class="block"><li><a href="#method.is_completed">is_completed</a></li><li><a href="#method.new">new</a></li><li><a href="#method.reset">reset</a></li><li><a href="#method.snooze">snooze</a></li><li><a href="#method.spin">spin</a></li></ul><h3><a href="#trait-implementations">Trait Implementations</a></h3><ul class="block"><li><a href="#impl-Debug-for-Backoff">Debug</a></li><li><a href="#impl-Default-for-Backoff">Default</a></li></ul><h3><a href="#synthetic-implementations">Auto Trait Implementations</a></h3><ul class="block"><li><a href="#impl-RefUnwindSafe-for-Backoff">!RefUnwindSafe</a></li><li><a href="#impl-Send-for-Backoff">Send</a></li><li><a href="#impl-Sync-for-Backoff">!Sync</a></li><li><a href="#impl-Unpin-for-Backoff">Unpin</a></li><li><a href="#impl-UnwindSafe-for-Backoff">UnwindSafe</a></li></ul><h3><a href="#blanket-implementations">Blanket Implementations</a></h3><ul class="block"><li><a href="#impl-Any-for-Backoff">Any</a></li><li><a href="#impl-Borrow%3CT%3E-for-Backoff">Borrow<T></a></li><li><a href="#impl-BorrowMut%3CT%3E-for-Backoff">BorrowMut<T></a></li><li><a href="#impl-From%3CT%3E-for-Backoff">From<T></a></li><li><a href="#impl-Into%3CU%3E-for-Backoff">Into<U></a></li><li><a href="#impl-TryFrom%3CU%3E-for-Backoff">TryFrom<U></a></li><li><a href="#impl-TryInto%3CU%3E-for-Backoff">TryInto<U></a></li></ul></section><h2><a href="index.html">In crossbeam_utils</a></h2></div></nav><main><div class="width-limiter"><nav class="sub"><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="main-heading"><h1 class="fqn">Struct <a href="index.html">crossbeam_utils</a>::<wbr><a class="struct" href="#">Backoff</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></h1><span class="out-of-band"><a class="srclink" href="../src/crossbeam_utils/backoff.rs.html#80-82">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">−</span>]</a></span></div><div class="item-decl"><pre class="rust struct"><code>pub struct Backoff { /* private fields */ }</code></pre></div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Performs exponential backoff in spin loops.</p> |
| <p>Backing off in spin loops reduces contention and improves overall performance.</p> |
| <p>This primitive can execute <em>YIELD</em> and <em>PAUSE</em> instructions, yield the current thread to the OS |
| scheduler, and tell when is a good time to block the thread using a different synchronization |
| mechanism. Each step of the back off procedure takes roughly twice as long as the previous |
| step.</p> |
| <h2 id="examples"><a href="#examples">Examples</a></h2> |
| <p>Backing off in a lock-free loop:</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>crossbeam_utils::Backoff; |
| <span class="kw">use </span>std::sync::atomic::AtomicUsize; |
| <span class="kw">use </span>std::sync::atomic::Ordering::SeqCst; |
| |
| <span class="kw">fn </span>fetch_mul(a: <span class="kw-2">&</span>AtomicUsize, b: usize) -> usize { |
| <span class="kw">let </span>backoff = Backoff::new(); |
| <span class="kw">loop </span>{ |
| <span class="kw">let </span>val = a.load(SeqCst); |
| <span class="kw">if </span>a.compare_exchange(val, val.wrapping_mul(b), SeqCst, SeqCst).is_ok() { |
| <span class="kw">return </span>val; |
| } |
| backoff.spin(); |
| } |
| }</code></pre></div> |
| <p>Waiting for an <a href="std::sync::atomic::AtomicBool"><code>AtomicBool</code></a> to become <code>true</code>:</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>crossbeam_utils::Backoff; |
| <span class="kw">use </span>std::sync::atomic::AtomicBool; |
| <span class="kw">use </span>std::sync::atomic::Ordering::SeqCst; |
| |
| <span class="kw">fn </span>spin_wait(ready: <span class="kw-2">&</span>AtomicBool) { |
| <span class="kw">let </span>backoff = Backoff::new(); |
| <span class="kw">while </span>!ready.load(SeqCst) { |
| backoff.snooze(); |
| } |
| }</code></pre></div> |
| <p>Waiting for an <a href="std::sync::atomic::AtomicBool"><code>AtomicBool</code></a> to become <code>true</code> and parking the thread after a long wait. |
| Note that whoever sets the atomic variable to <code>true</code> must notify the parked thread by calling |
| <a href="std::thread::Thread::unpark"><code>unpark()</code></a>:</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>crossbeam_utils::Backoff; |
| <span class="kw">use </span>std::sync::atomic::AtomicBool; |
| <span class="kw">use </span>std::sync::atomic::Ordering::SeqCst; |
| <span class="kw">use </span>std::thread; |
| |
| <span class="kw">fn </span>blocking_wait(ready: <span class="kw-2">&</span>AtomicBool) { |
| <span class="kw">let </span>backoff = Backoff::new(); |
| <span class="kw">while </span>!ready.load(SeqCst) { |
| <span class="kw">if </span>backoff.is_completed() { |
| thread::park(); |
| } <span class="kw">else </span>{ |
| backoff.snooze(); |
| } |
| } |
| }</code></pre></div> |
| </div></details><h2 id="implementations" class="small-section-header">Implementations<a href="#implementations" class="anchor"></a></h2><div id="implementations-list"><details class="rustdoc-toggle implementors-toggle" open><summary><section id="impl-Backoff" class="impl has-srclink"><a class="srclink rightside" href="../src/crossbeam_utils/backoff.rs.html#84-281">source</a><a href="#impl-Backoff" class="anchor"></a><h3 class="code-header">impl <a class="struct" href="struct.Backoff.html" title="struct crossbeam_utils::Backoff">Backoff</a></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.new" class="method has-srclink"><a class="srclink rightside" href="../src/crossbeam_utils/backoff.rs.html#95-97">source</a><h4 class="code-header">pub fn <a href="#method.new" class="fnname">new</a>() -> Self</h4></section></summary><div class="docblock"><p>Creates a new <code>Backoff</code>.</p> |
| <h5 id="examples-1"><a href="#examples-1">Examples</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>crossbeam_utils::Backoff; |
| |
| <span class="kw">let </span>backoff = Backoff::new();</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.reset" class="method has-srclink"><a class="srclink rightside" href="../src/crossbeam_utils/backoff.rs.html#110-112">source</a><h4 class="code-header">pub fn <a href="#method.reset" class="fnname">reset</a>(&self)</h4></section></summary><div class="docblock"><p>Resets the <code>Backoff</code>.</p> |
| <h5 id="examples-2"><a href="#examples-2">Examples</a></h5> |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>crossbeam_utils::Backoff; |
| |
| <span class="kw">let </span>backoff = Backoff::new(); |
| backoff.reset();</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.spin" class="method has-srclink"><a class="srclink rightside" href="../src/crossbeam_utils/backoff.rs.html#146-157">source</a><h4 class="code-header">pub fn <a href="#method.spin" class="fnname">spin</a>(&self)</h4></section></summary><div class="docblock"><p>Backs off in a lock-free loop.</p> |
| <p>This method should be used when we need to retry an operation because another thread made |
| progress.</p> |
| <p>The processor may yield using the <em>YIELD</em> or <em>PAUSE</em> instruction.</p> |
| <h5 id="examples-3"><a href="#examples-3">Examples</a></h5> |
| <p>Backing off in a lock-free loop:</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>crossbeam_utils::Backoff; |
| <span class="kw">use </span>std::sync::atomic::AtomicUsize; |
| <span class="kw">use </span>std::sync::atomic::Ordering::SeqCst; |
| |
| <span class="kw">fn </span>fetch_mul(a: <span class="kw-2">&</span>AtomicUsize, b: usize) -> usize { |
| <span class="kw">let </span>backoff = Backoff::new(); |
| <span class="kw">loop </span>{ |
| <span class="kw">let </span>val = a.load(SeqCst); |
| <span class="kw">if </span>a.compare_exchange(val, val.wrapping_mul(b), SeqCst, SeqCst).is_ok() { |
| <span class="kw">return </span>val; |
| } |
| backoff.spin(); |
| } |
| } |
| |
| <span class="kw">let </span>a = AtomicUsize::new(<span class="number">7</span>); |
| <span class="macro">assert_eq!</span>(fetch_mul(<span class="kw-2">&</span>a, <span class="number">8</span>), <span class="number">7</span>); |
| <span class="macro">assert_eq!</span>(a.load(SeqCst), <span class="number">56</span>);</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.snooze" class="method has-srclink"><a class="srclink rightside" href="../src/crossbeam_utils/backoff.rs.html#209-233">source</a><h4 class="code-header">pub fn <a href="#method.snooze" class="fnname">snooze</a>(&self)</h4></section></summary><div class="docblock"><p>Backs off in a blocking loop.</p> |
| <p>This method should be used when we need to wait for another thread to make progress.</p> |
| <p>The processor may yield using the <em>YIELD</em> or <em>PAUSE</em> instruction and the current thread |
| may yield by giving up a timeslice to the OS scheduler.</p> |
| <p>In <code>#[no_std]</code> environments, this method is equivalent to <a href="struct.Backoff.html#method.spin"><code>spin</code></a>.</p> |
| <p>If possible, use <a href="struct.Backoff.html#method.is_completed"><code>is_completed</code></a> to check when it is advised to stop using backoff and |
| block the current thread using a different synchronization mechanism instead.</p> |
| <h5 id="examples-4"><a href="#examples-4">Examples</a></h5> |
| <p>Waiting for an <a href="std::sync::atomic::AtomicBool"><code>AtomicBool</code></a> to become <code>true</code>:</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>crossbeam_utils::Backoff; |
| <span class="kw">use </span>std::sync::Arc; |
| <span class="kw">use </span>std::sync::atomic::AtomicBool; |
| <span class="kw">use </span>std::sync::atomic::Ordering::SeqCst; |
| <span class="kw">use </span>std::thread; |
| <span class="kw">use </span>std::time::Duration; |
| |
| <span class="kw">fn </span>spin_wait(ready: <span class="kw-2">&</span>AtomicBool) { |
| <span class="kw">let </span>backoff = Backoff::new(); |
| <span class="kw">while </span>!ready.load(SeqCst) { |
| backoff.snooze(); |
| } |
| } |
| |
| <span class="kw">let </span>ready = Arc::new(AtomicBool::new(<span class="bool-val">false</span>)); |
| <span class="kw">let </span>ready2 = ready.clone(); |
| |
| thread::spawn(<span class="kw">move </span>|| { |
| thread::sleep(Duration::from_millis(<span class="number">100</span>)); |
| ready2.store(<span class="bool-val">true</span>, SeqCst); |
| }); |
| |
| <span class="macro">assert_eq!</span>(ready.load(SeqCst), <span class="bool-val">false</span>); |
| spin_wait(<span class="kw-2">&</span>ready); |
| <span class="macro">assert_eq!</span>(ready.load(SeqCst), <span class="bool-val">true</span>);</code></pre></div> |
| </div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.is_completed" class="method has-srclink"><a class="srclink rightside" href="../src/crossbeam_utils/backoff.rs.html#278-280">source</a><h4 class="code-header">pub fn <a href="#method.is_completed" class="fnname">is_completed</a>(&self) -> bool</h4></section></summary><div class="docblock"><p>Returns <code>true</code> if exponential backoff has completed and blocking the thread is advised.</p> |
| <h5 id="examples-5"><a href="#examples-5">Examples</a></h5> |
| <p>Waiting for an <a href="std::sync::atomic::AtomicBool"><code>AtomicBool</code></a> to become <code>true</code> and parking the thread after a long wait:</p> |
| |
| <div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>crossbeam_utils::Backoff; |
| <span class="kw">use </span>std::sync::Arc; |
| <span class="kw">use </span>std::sync::atomic::AtomicBool; |
| <span class="kw">use </span>std::sync::atomic::Ordering::SeqCst; |
| <span class="kw">use </span>std::thread; |
| <span class="kw">use </span>std::time::Duration; |
| |
| <span class="kw">fn </span>blocking_wait(ready: <span class="kw-2">&</span>AtomicBool) { |
| <span class="kw">let </span>backoff = Backoff::new(); |
| <span class="kw">while </span>!ready.load(SeqCst) { |
| <span class="kw">if </span>backoff.is_completed() { |
| thread::park(); |
| } <span class="kw">else </span>{ |
| backoff.snooze(); |
| } |
| } |
| } |
| |
| <span class="kw">let </span>ready = Arc::new(AtomicBool::new(<span class="bool-val">false</span>)); |
| <span class="kw">let </span>ready2 = ready.clone(); |
| <span class="kw">let </span>waiter = thread::current(); |
| |
| thread::spawn(<span class="kw">move </span>|| { |
| thread::sleep(Duration::from_millis(<span class="number">100</span>)); |
| ready2.store(<span class="bool-val">true</span>, SeqCst); |
| waiter.unpark(); |
| }); |
| |
| <span class="macro">assert_eq!</span>(ready.load(SeqCst), <span class="bool-val">false</span>); |
| blocking_wait(<span class="kw-2">&</span>ready); |
| <span class="macro">assert_eq!</span>(ready.load(SeqCst), <span class="bool-val">true</span>);</code></pre></div> |
| </div></details></div></details></div><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><section id="impl-Debug-for-Backoff" class="impl has-srclink"><a class="srclink rightside" href="../src/crossbeam_utils/backoff.rs.html#283-290">source</a><a href="#impl-Debug-for-Backoff" class="anchor"></a><h3 class="code-header">impl Debug for <a class="struct" href="struct.Backoff.html" title="struct crossbeam_utils::Backoff">Backoff</a></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.fmt" class="method trait-impl has-srclink"><a class="srclink rightside" href="../src/crossbeam_utils/backoff.rs.html#284-289">source</a><a href="#method.fmt" class="anchor"></a><h4 class="code-header">fn <a class="fnname">fmt</a>(&self, f: &mut Formatter<'_>) -> Result</h4></section></summary><div class='docblock'>Formats the value using the given formatter. <a>Read more</a></div></details></div></details><details class="rustdoc-toggle implementors-toggle" open><summary><section id="impl-Default-for-Backoff" class="impl has-srclink"><a class="srclink rightside" href="../src/crossbeam_utils/backoff.rs.html#292-296">source</a><a href="#impl-Default-for-Backoff" class="anchor"></a><h3 class="code-header">impl Default for <a class="struct" href="struct.Backoff.html" title="struct crossbeam_utils::Backoff">Backoff</a></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.default" class="method trait-impl has-srclink"><a class="srclink rightside" href="../src/crossbeam_utils/backoff.rs.html#293-295">source</a><a href="#method.default" class="anchor"></a><h4 class="code-header">fn <a class="fnname">default</a>() -> <a class="struct" href="struct.Backoff.html" title="struct crossbeam_utils::Backoff">Backoff</a></h4></section></summary><div class='docblock'>Returns the “default value” for a type. <a>Read more</a></div></details></div></details></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"><section id="impl-RefUnwindSafe-for-Backoff" class="impl has-srclink"><a href="#impl-RefUnwindSafe-for-Backoff" class="anchor"></a><h3 class="code-header">impl !RefUnwindSafe for <a class="struct" href="struct.Backoff.html" title="struct crossbeam_utils::Backoff">Backoff</a></h3></section><section id="impl-Send-for-Backoff" class="impl has-srclink"><a href="#impl-Send-for-Backoff" class="anchor"></a><h3 class="code-header">impl Send for <a class="struct" href="struct.Backoff.html" title="struct crossbeam_utils::Backoff">Backoff</a></h3></section><section id="impl-Sync-for-Backoff" class="impl has-srclink"><a href="#impl-Sync-for-Backoff" class="anchor"></a><h3 class="code-header">impl !Sync for <a class="struct" href="struct.Backoff.html" title="struct crossbeam_utils::Backoff">Backoff</a></h3></section><section id="impl-Unpin-for-Backoff" class="impl has-srclink"><a href="#impl-Unpin-for-Backoff" class="anchor"></a><h3 class="code-header">impl Unpin for <a class="struct" href="struct.Backoff.html" title="struct crossbeam_utils::Backoff">Backoff</a></h3></section><section id="impl-UnwindSafe-for-Backoff" class="impl has-srclink"><a href="#impl-UnwindSafe-for-Backoff" class="anchor"></a><h3 class="code-header">impl UnwindSafe for <a class="struct" href="struct.Backoff.html" title="struct crossbeam_utils::Backoff">Backoff</a></h3></section></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"><summary><section id="impl-Any-for-Backoff" class="impl has-srclink"><a href="#impl-Any-for-Backoff" class="anchor"></a><h3 class="code-header">impl<T> Any for T<span class="where fmt-newline">where<br> T: 'static + ?Sized,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.type_id" class="method trait-impl has-srclink"><a href="#method.type_id" class="anchor"></a><h4 class="code-header">fn <a class="fnname">type_id</a>(&self) -> TypeId</h4></section></summary><div class='docblock'>Gets the <code>TypeId</code> of <code>self</code>. <a>Read more</a></div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-Borrow%3CT%3E-for-Backoff" class="impl has-srclink"><a href="#impl-Borrow%3CT%3E-for-Backoff" class="anchor"></a><h3 class="code-header">impl<T> Borrow<T> for T<span class="where fmt-newline">where<br> T: ?Sized,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.borrow" class="method trait-impl has-srclink"><span class="since rightside" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/91522" title="Tracking issue for const_borrow">unstable</a></span><a href="#method.borrow" class="anchor"></a><h4 class="code-header">fn <a class="fnname">borrow</a>(&self) -> &T</h4></section></summary><div class='docblock'>Immutably borrows from an owned value. <a>Read more</a></div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-BorrowMut%3CT%3E-for-Backoff" class="impl has-srclink"><a href="#impl-BorrowMut%3CT%3E-for-Backoff" class="anchor"></a><h3 class="code-header">impl<T> BorrowMut<T> for T<span class="where fmt-newline">where<br> T: ?Sized,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.borrow_mut" class="method trait-impl has-srclink"><span class="since rightside" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/91522" title="Tracking issue for const_borrow">unstable</a></span><a href="#method.borrow_mut" class="anchor"></a><h4 class="code-header">fn <a class="fnname">borrow_mut</a>(&mut self) -> &mut T</h4></section></summary><div class='docblock'>Mutably borrows from an owned value. <a>Read more</a></div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-From%3CT%3E-for-Backoff" class="impl has-srclink"><a href="#impl-From%3CT%3E-for-Backoff" class="anchor"></a><h3 class="code-header">impl<T> From<T> for T</h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.from" class="method trait-impl has-srclink"><span class="since rightside" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/88674" title="Tracking issue for const_convert">unstable</a></span><a href="#method.from" class="anchor"></a><h4 class="code-header">fn <a class="fnname">from</a>(t: T) -> T</h4></section></summary><div class="docblock"><p>Returns the argument unchanged.</p> |
| </div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-Into%3CU%3E-for-Backoff" class="impl has-srclink"><a href="#impl-Into%3CU%3E-for-Backoff" class="anchor"></a><h3 class="code-header">impl<T, U> Into<U> for T<span class="where fmt-newline">where<br> U: From<T>,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle method-toggle" open><summary><section id="method.into" class="method trait-impl has-srclink"><span class="since rightside" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/88674" title="Tracking issue for const_convert">unstable</a></span><a href="#method.into" class="anchor"></a><h4 class="code-header">fn <a class="fnname">into</a>(self) -> 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>[From]<T> for U</code> chooses to do.</p> |
| </div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-TryFrom%3CU%3E-for-Backoff" class="impl has-srclink"><a href="#impl-TryFrom%3CU%3E-for-Backoff" class="anchor"></a><h3 class="code-header">impl<T, U> TryFrom<U> for T<span class="where fmt-newline">where<br> U: Into<T>,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle" open><summary><section id="associatedtype.Error-1" class="associatedtype trait-impl has-srclink"><a href="#associatedtype.Error-1" class="anchor"></a><h4 class="code-header">type <a class="associatedtype">Error</a> = Infallible</h4></section></summary><div class='docblock'>The type returned in the event of a conversion error.</div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.try_from" class="method trait-impl has-srclink"><span class="since rightside" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/88674" title="Tracking issue for const_convert">unstable</a></span><a href="#method.try_from" class="anchor"></a><h4 class="code-header">fn <a class="fnname">try_from</a>(value: U) -> Result<T, <T as TryFrom<U>>::Error></h4></section></summary><div class='docblock'>Performs the conversion.</div></details></div></details><details class="rustdoc-toggle implementors-toggle"><summary><section id="impl-TryInto%3CU%3E-for-Backoff" class="impl has-srclink"><a href="#impl-TryInto%3CU%3E-for-Backoff" class="anchor"></a><h3 class="code-header">impl<T, U> TryInto<U> for T<span class="where fmt-newline">where<br> U: TryFrom<T>,</span></h3></section></summary><div class="impl-items"><details class="rustdoc-toggle" open><summary><section id="associatedtype.Error" class="associatedtype trait-impl has-srclink"><a href="#associatedtype.Error" class="anchor"></a><h4 class="code-header">type <a class="associatedtype">Error</a> = <U as TryFrom<T>>::Error</h4></section></summary><div class='docblock'>The type returned in the event of a conversion error.</div></details><details class="rustdoc-toggle method-toggle" open><summary><section id="method.try_into" class="method trait-impl has-srclink"><span class="since rightside" title="const unstable">const: <a href="https://github.com/rust-lang/rust/issues/88674" title="Tracking issue for const_convert">unstable</a></span><a href="#method.try_into" class="anchor"></a><h4 class="code-header">fn <a class="fnname">try_into</a>(self) -> Result<U, <U as TryFrom<T>>::Error></h4></section></summary><div class='docblock'>Performs the conversion.</div></details></div></details></div></section></div></main><div id="rustdoc-vars" data-root-path="../" data-current-crate="crossbeam_utils" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
