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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="API documentation for the Rust `EnteredSpan` struct in crate `tracing`."><meta name="keywords" content="rust, rustlang, rust-lang, EnteredSpan"><title>tracing::span::EnteredSpan - Rust</title><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="../../light.css" id="themeStyle"><link rel="stylesheet" type="text/css" href="../../dark.css" disabled ><link rel="stylesheet" type="text/css" href="../../ayu.css" disabled ><script id="default-settings"></script><script src="../../storage.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="icon" type="image/svg+xml" href="../../favicon.svg">
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<link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><style type="text/css">#crate-search{background-image:url("../../down-arrow.svg");}</style></head><body class="rustdoc struct"><!--[if lte IE 8]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu">☰</div><a href='../../tracing/index.html'><div class='logo-container'><img src='https://raw.githubusercontent.com/tokio-rs/tracing/master/assets/logo-type.png' alt='logo'></div></a><p class="location">Struct EnteredSpan</p><div class="sidebar-elems"><div class="block items"><a class="sidebar-title" href="#implementations">Methods</a><div class="sidebar-links"><a href="#method.exit">exit</a></div><a class="sidebar-title" href="#deref-methods-Span">Methods from Deref<Target=Span></a><div class="sidebar-links"><a href="#method.enter">enter</a><a href="#method.field">field</a><a href="#method.follows_from">follows_from</a><a href="#method.has_field">has_field</a><a href="#method.id">id</a><a href="#method.in_scope">in_scope</a><a href="#method.is_disabled">is_disabled</a><a href="#method.is_none">is_none</a><a href="#method.metadata">metadata</a><a href="#method.record">record</a><a href="#method.record_all">record_all</a><a href="#method.with_subscriber">with_subscriber</a></div><a class="sidebar-title" href="#trait-implementations">Trait Implementations</a><div class="sidebar-links"><a href="#impl-Debug">Debug</a><a href="#impl-Deref">Deref</a><a href="#impl-Drop">Drop</a></div><a class="sidebar-title" href="#synthetic-implementations">Auto Trait Implementations</a><div class="sidebar-links"><a href="#impl-RefUnwindSafe">!RefUnwindSafe</a><a href="#impl-Send">!Send</a><a href="#impl-Sync">Sync</a><a href="#impl-Unpin">Unpin</a><a href="#impl-UnwindSafe">!UnwindSafe</a></div><a class="sidebar-title" href="#blanket-implementations">Blanket Implementations</a><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-Instrument">Instrument</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><p class="location"><a href="../index.html">tracing</a>::<wbr><a href="index.html">span</a></p><div id="sidebar-vars" data-name="EnteredSpan" data-ty="struct" data-relpath=""></div><script defer src="sidebar-items.js"></script></div></nav><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!" aria-haspopup="menu"><img src="../../brush.svg" width="18" alt="Pick another theme!"></button><div id="theme-choices" role="menu"></div></div><script src="../../theme.js"></script><nav class="sub"><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" disabled autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"></div><button type="button" class="help-button">?</button>
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<a id="settings-menu" href="../../settings.html"><img src="../../wheel.svg" width="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><h1 class="fqn"><span class="in-band">Struct <a href="../index.html">tracing</a>::<wbr><a href="index.html">span</a>::<wbr><a class="struct" href="">EnteredSpan</a></span><span class="out-of-band"><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="../../src/tracing/span.rs.html#414-424" title="goto source code">[src]</a></span></h1><div class="docblock type-decl hidden-by-usual-hider"><pre class="rust struct"><span class="docblock attributes top-attr">#[must_use = "once a span has been entered, it should be exited"]</span>pub struct EnteredSpan { /* fields omitted */ }</pre></div><div class="docblock"><p>An owned version of <a href="../../tracing/span/struct.Entered.html" title="Entered"><code>Entered</code></a>, a guard representing a span which has been
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entered and is currently executing.</p>
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<p>When the guard is dropped, the span will be exited.</p>
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<p>This is returned by the <a href="../../tracing/struct.Span.html#method.entered"><code>Span::entered</code></a> function.</p>
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</div><h2 id="implementations" class="small-section-header">Implementations<a href="#implementations" class="anchor"></a></h2><h3 id="impl" class="impl"><code class="in-band">impl <a class="struct" href="../../tracing/span/struct.EnteredSpan.html" title="struct tracing::span::EnteredSpan">EnteredSpan</a></code><a href="#impl" class="anchor"></a><a class="srclink" href="../../src/tracing/span.rs.html#1405-1414" title="goto source code">[src]</a></h3><div class="impl-items"><h4 id="method.exit" class="method"><code>pub fn <a href="#method.exit" class="fnname">exit</a>(self) -> <a class="struct" href="../../tracing/struct.Span.html" title="struct tracing::Span">Span</a></code><a class="srclink" href="../../src/tracing/span.rs.html#1408-1413" title="goto source code">[src]</a></h4><div class="docblock"><p>Exits this span, returning the underlying <a href="../../tracing/struct.Span.html" title="Span"><code>Span</code></a>.</p>
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</div></div><h2 id="deref-methods-Span" class="small-section-header">Methods from <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/deref/trait.Deref.html" title="trait core::ops::deref::Deref">Deref</a><Target = <a class="struct" href="../../tracing/struct.Span.html" title="struct tracing::Span">Span</a>><a href="#deref-methods-Span" class="anchor"></a></h2><div class="impl-items"><h4 id="method.enter" class="method"><code>pub fn <a href="#method.enter" class="fnname">enter</a>(&self) -> <a class="struct" href="../../tracing/span/struct.Entered.html" title="struct tracing::span::Entered">Entered</a><'_></code><a class="srclink" href="../../src/tracing/span.rs.html#791-794" title="goto source code">[src]</a></h4><div class="docblock"><p>Enters this span, returning a guard that will exit the span when dropped.</p>
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<p>If this span is enabled by the current subscriber, then this function will
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call <a href="../subscriber/trait.Subscriber.html#method.enter"><code>Subscriber::enter</code></a> with the span's <a href="../struct.Id.html"><code>Id</code></a>, and dropping the guard
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will call <a href="../subscriber/trait.Subscriber.html#method.exit"><code>Subscriber::exit</code></a>. If the span is disabled, this does
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nothing.</p>
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<h1 id="in-asynchronous-code" class="section-header"><a href="#in-asynchronous-code">In Asynchronous Code</a></h1>
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<p><strong>Warning</strong>: in asynchronous code that uses <a href="https://rust-lang.github.io/async-book/01_getting_started/04_async_await_primer.html">async/await syntax</a>,
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<code>Span::enter</code> should be used very carefully or avoided entirely. Holding
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the drop guard returned by <code>Span::enter</code> across <code>.await</code> points will
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result in incorrect traces.</p>
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<p>For example,</p>
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<div class="example-wrap"><pre class="rust rust-example-rendered">
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<span class="kw">async</span> <span class="kw">fn</span> <span class="ident">my_async_function</span>() {
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<span class="kw">let</span> <span class="ident">span</span> <span class="op">=</span> <span class="macro">info_span</span><span class="macro">!</span>(<span class="string">"my_async_function"</span>);
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<span class="comment">// THIS WILL RESULT IN INCORRECT TRACES</span>
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<span class="kw">let</span> <span class="ident">_enter</span> <span class="op">=</span> <span class="ident">span</span>.<span class="ident">enter</span>();
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<span class="ident">some_other_async_function</span>().<span class="kw">await</span>;
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<span class="comment">// ...</span>
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}</pre></div>
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<p>The drop guard returned by <code>Span::enter</code> exits the span when it is
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dropped. When an async function or async block yields at an <code>.await</code>
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point, the current scope is <em>exited</em>, but values in that scope are
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<strong>not</strong> dropped (because the async block will eventually resume
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execution from that await point). This means that <em>another</em> task will
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begin executing while <em>remaining</em> in the entered span. This results in
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an incorrect trace.</p>
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<p>Instead of using <code>Span::enter</code> in asynchronous code, prefer the
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following:</p>
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<ul>
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<li>
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<p>To enter a span for a synchronous section of code within an async
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block or function, prefer <a href="#method.in_scope"><code>Span::in_scope</code></a>. Since <code>in_scope</code> takes a
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synchronous closure and exits the span when the closure returns, the
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span will always be exited before the next await point. For example:</p>
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<div class="example-wrap"><pre class="rust rust-example-rendered">
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<span class="kw">async</span> <span class="kw">fn</span> <span class="ident">my_async_function</span>() {
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<span class="kw">let</span> <span class="ident">span</span> <span class="op">=</span> <span class="macro">info_span</span><span class="macro">!</span>(<span class="string">"my_async_function"</span>);
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<span class="kw">let</span> <span class="ident">some_value</span> <span class="op">=</span> <span class="ident">span</span>.<span class="ident">in_scope</span>(<span class="op">|</span><span class="op">|</span> {
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<span class="comment">// run some synchronous code inside the span...</span>
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});
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<span class="comment">// This is okay! The span has already been exited before we reach</span>
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<span class="comment">// the await point.</span>
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<span class="ident">some_other_async_function</span>(<span class="ident">some_value</span>).<span class="kw">await</span>;
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<span class="comment">// ...</span>
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}</pre></div>
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</li>
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<li>
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<p>For instrumenting asynchronous code, <code>tracing</code> provides the
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<a href="https://docs.rs/tracing/latest/tracing/trait.Instrument.html"><code>Future::instrument</code> combinator</a> for
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attaching a span to a future (async function or block). This will
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enter the span <em>every</em> time the future is polled, and exit it whenever
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the future yields.</p>
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<p><code>Instrument</code> can be used with an async block inside an async function:</p>
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<div class='information'><div class='tooltip ignore'>ⓘ</div></div><div class="example-wrap"><pre class="rust rust-example-rendered ignore">
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<span class="kw">use</span> <span class="ident">tracing</span>::<span class="ident">Instrument</span>;
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<span class="kw">async</span> <span class="kw">fn</span> <span class="ident">my_async_function</span>() {
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<span class="kw">let</span> <span class="ident">span</span> <span class="op">=</span> <span class="macro">info_span</span><span class="macro">!</span>(<span class="string">"my_async_function"</span>);
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<span class="kw">async</span> <span class="kw">move</span> {
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<span class="comment">// This is correct! If we yield here, the span will be exited,</span>
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<span class="comment">// and re-entered when we resume.</span>
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<span class="ident">some_other_async_function</span>().<span class="kw">await</span>;
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<span class="comment">//more asynchronous code inside the span...</span>
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}
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<span class="comment">// instrument the async block with the span...</span>
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.<span class="ident">instrument</span>(<span class="ident">span</span>)
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<span class="comment">// ...and await it.</span>
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.<span class="kw">await</span>
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}</pre></div>
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<p>It can also be used to instrument calls to async functions at the
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callsite:</p>
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<div class='information'><div class='tooltip ignore'>ⓘ</div></div><div class="example-wrap"><pre class="rust rust-example-rendered ignore">
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<span class="kw">use</span> <span class="ident">tracing</span>::<span class="ident">Instrument</span>;
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<span class="kw">async</span> <span class="kw">fn</span> <span class="ident">my_async_function</span>() {
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<span class="kw">let</span> <span class="ident">some_value</span> <span class="op">=</span> <span class="ident">some_other_async_function</span>()
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.<span class="ident">instrument</span>(<span class="macro">debug_span</span><span class="macro">!</span>(<span class="string">"some_other_async_function"</span>))
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.<span class="kw">await</span>;
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<span class="comment">// ...</span>
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}</pre></div>
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</li>
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<li>
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<p>The <a href="../../attr.instrument.html"><code>#[instrument]</code> attribute macro</a> can automatically generate
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correct code when used on an async function:</p>
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<div class='information'><div class='tooltip ignore'>ⓘ</div></div><div class="example-wrap"><pre class="rust rust-example-rendered ignore">
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<span class="attribute">#[<span class="ident">tracing</span>::<span class="ident">instrument</span>(<span class="ident">level</span> <span class="op">=</span> <span class="string">"info"</span>)]</span>
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<span class="kw">async</span> <span class="kw">fn</span> <span class="ident">my_async_function</span>() {
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<span class="comment">// This is correct! If we yield here, the span will be exited,</span>
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<span class="comment">// and re-entered when we resume.</span>
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<span class="ident">some_other_async_function</span>().<span class="kw">await</span>;
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<span class="comment">// ...</span>
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}</pre></div>
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</li>
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</ul>
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<h1 id="examples" class="section-header"><a href="#examples">Examples</a></h1>
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<div class="example-wrap"><pre class="rust rust-example-rendered">
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<span class="attribute">#[<span class="ident">macro_use</span>]</span> <span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">tracing</span>;
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<span class="kw">let</span> <span class="ident">span</span> <span class="op">=</span> <span class="macro">span</span><span class="macro">!</span>(<span class="ident">Level</span>::<span class="ident">INFO</span>, <span class="string">"my_span"</span>);
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<span class="kw">let</span> <span class="ident">guard</span> <span class="op">=</span> <span class="ident">span</span>.<span class="ident">enter</span>();
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<span class="comment">// code here is within the span</span>
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<span class="ident">drop</span>(<span class="ident">guard</span>);
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<span class="comment">// code here is no longer within the span</span>
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</pre></div>
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<p>Guards need not be explicitly dropped:</p>
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<div class="example-wrap"><pre class="rust rust-example-rendered">
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<span class="attribute">#[<span class="ident">macro_use</span>]</span> <span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">tracing</span>;
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<span class="kw">fn</span> <span class="ident">my_function</span>() <span class="op">-</span><span class="op">></span> <span class="ident">String</span> {
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<span class="comment">// enter a span for the duration of this function.</span>
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<span class="kw">let</span> <span class="ident">span</span> <span class="op">=</span> <span class="macro">trace_span</span><span class="macro">!</span>(<span class="string">"my_function"</span>);
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<span class="kw">let</span> <span class="ident">_enter</span> <span class="op">=</span> <span class="ident">span</span>.<span class="ident">enter</span>();
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<span class="comment">// anything happening in functions we call is still inside the span...</span>
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<span class="ident">my_other_function</span>();
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<span class="comment">// returning from the function drops the guard, exiting the span.</span>
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<span class="kw">return</span> <span class="string">"Hello world"</span>.<span class="ident">to_owned</span>();
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}
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<span class="kw">fn</span> <span class="ident">my_other_function</span>() {
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<span class="comment">// ...</span>
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}</pre></div>
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<p>Sub-scopes may be created to limit the duration for which the span is
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entered:</p>
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<div class="example-wrap"><pre class="rust rust-example-rendered">
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<span class="attribute">#[<span class="ident">macro_use</span>]</span> <span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">tracing</span>;
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<span class="kw">let</span> <span class="ident">span</span> <span class="op">=</span> <span class="macro">info_span</span><span class="macro">!</span>(<span class="string">"my_great_span"</span>);
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{
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<span class="kw">let</span> <span class="ident">_enter</span> <span class="op">=</span> <span class="ident">span</span>.<span class="ident">enter</span>();
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<span class="comment">// this event occurs inside the span.</span>
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<span class="macro">info</span><span class="macro">!</span>(<span class="string">"i'm in the span!"</span>);
|
||
|
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<span class="comment">// exiting the scope drops the guard, exiting the span.</span>
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||
}
|
||
|
||
<span class="comment">// this event is not inside the span.</span>
|
||
<span class="macro">info</span><span class="macro">!</span>(<span class="string">"i'm outside the span!"</span>)</pre></div>
|
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</div><h4 id="method.in_scope" class="method"><code>pub fn <a href="#method.in_scope" class="fnname">in_scope</a><F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>() -> T, T>(&self, f: F) -> T</code><a class="srclink" href="../../src/tracing/span.rs.html#980-983" title="goto source code">[src]</a></h4><div class="docblock"><p>Executes the given function in the context of this span.</p>
|
||
<p>If this span is enabled, then this function enters the span, invokes <code>f</code>
|
||
and then exits the span. If the span is disabled, <code>f</code> will still be
|
||
invoked, but in the context of the currently-executing span (if there is
|
||
one).</p>
|
||
<p>Returns the result of evaluating <code>f</code>.</p>
|
||
<h1 id="examples-1" class="section-header"><a href="#examples-1">Examples</a></h1>
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||
<span class="kw">let</span> <span class="ident">my_span</span> <span class="op">=</span> <span class="macro">span</span><span class="macro">!</span>(<span class="ident">Level</span>::<span class="ident">TRACE</span>, <span class="string">"my_span"</span>);
|
||
|
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<span class="ident">my_span</span>.<span class="ident">in_scope</span>(<span class="op">|</span><span class="op">|</span> {
|
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<span class="comment">// this event occurs within the span.</span>
|
||
<span class="macro">trace</span><span class="macro">!</span>(<span class="string">"i'm in the span!"</span>);
|
||
});
|
||
|
||
<span class="comment">// this event occurs outside the span.</span>
|
||
<span class="macro">trace</span><span class="macro">!</span>(<span class="string">"i'm not in the span!"</span>);</pre></div>
|
||
<p>Calling a function and returning the result:</p>
|
||
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||
<span class="kw">fn</span> <span class="ident">hello_world</span>() <span class="op">-</span><span class="op">></span> <span class="ident">String</span> {
|
||
<span class="string">"Hello world!"</span>.<span class="ident">to_owned</span>()
|
||
}
|
||
|
||
<span class="kw">let</span> <span class="ident">span</span> <span class="op">=</span> <span class="macro">info_span</span><span class="macro">!</span>(<span class="string">"hello_world"</span>);
|
||
<span class="comment">// the span will be entered for the duration of the call to</span>
|
||
<span class="comment">// `hello_world`.</span>
|
||
<span class="kw">let</span> <span class="ident">a_string</span> <span class="op">=</span> <span class="ident">span</span>.<span class="ident">in_scope</span>(<span class="ident">hello_world</span>);</pre></div>
|
||
</div><h4 id="method.field" class="method"><code>pub fn <a href="#method.field" class="fnname">field</a><Q: ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>>(&self, field: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&</a>Q) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a><<a class="struct" href="../../tracing/field/struct.Field.html" title="struct tracing::field::Field">Field</a>> <span class="where fmt-newline">where<br> Q: <a class="trait" href="../../tracing/field/trait.AsField.html" title="trait tracing::field::AsField">AsField</a>, </span></code><a class="srclink" href="../../src/tracing/span.rs.html#987-992" title="goto source code">[src]</a></h4><div class="docblock"><p>Returns a <a href="../field/struct.Field.html"><code>Field</code></a> for the field with the
|
||
given <code>name</code>, if one exists,</p>
|
||
</div><h4 id="method.has_field" class="method"><code>pub fn <a href="#method.has_field" class="fnname">has_field</a><Q: ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>>(&self, field: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&</a>Q) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a> <span class="where fmt-newline">where<br> Q: <a class="trait" href="../../tracing/field/trait.AsField.html" title="trait tracing::field::AsField">AsField</a>, </span></code><a class="srclink" href="../../src/tracing/span.rs.html#997-1002" title="goto source code">[src]</a></h4><div class="docblock"><p>Returns true if this <code>Span</code> has a field for the given
|
||
<a href="../field/struct.Field.html"><code>Field</code></a> or field name.</p>
|
||
</div><h4 id="method.record" class="method"><code>pub fn <a href="#method.record" class="fnname">record</a><Q: ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>, V>(&self, field: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&</a>Q, value: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&</a>V) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&</a>Self <span class="where fmt-newline">where<br> Q: <a class="trait" href="../../tracing/field/trait.AsField.html" title="trait tracing::field::AsField">AsField</a>,<br> V: <a class="trait" href="../../tracing/trait.Value.html" title="trait tracing::Value">Value</a>, </span></code><a class="srclink" href="../../src/tracing/span.rs.html#1076-1092" title="goto source code">[src]</a></h4><div class="docblock"><p>Records that the field described by <code>field</code> has the value <code>value</code>.</p>
|
||
<p>This may be used with <a href="../field/struct.Empty.html"><code>field::Empty</code></a> to declare fields whose values
|
||
are not known when the span is created, and record them later:</p>
|
||
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||
<span class="kw">use</span> <span class="ident">tracing</span>::{<span class="ident">trace_span</span>, <span class="ident">field</span>};
|
||
|
||
<span class="comment">// Create a span with two fields: `greeting`, with the value "hello world", and</span>
|
||
<span class="comment">// `parting`, without a value.</span>
|
||
<span class="kw">let</span> <span class="ident">span</span> <span class="op">=</span> <span class="macro">trace_span</span><span class="macro">!</span>(<span class="string">"my_span"</span>, <span class="ident">greeting</span> <span class="op">=</span> <span class="string">"hello world"</span>, <span class="ident">parting</span> <span class="op">=</span> <span class="ident">field</span>::<span class="ident">Empty</span>);
|
||
|
||
<span class="comment">// ...</span>
|
||
|
||
<span class="comment">// Now, record a value for parting as well.</span>
|
||
<span class="comment">// (note that the field name is passed as a string slice)</span>
|
||
<span class="ident">span</span>.<span class="ident">record</span>(<span class="string">"parting"</span>, <span class="kw-2">&</span><span class="string">"goodbye world!"</span>);</pre></div>
|
||
<p>However, it may also be used to record a <em>new</em> value for a field whose
|
||
value was already recorded:</p>
|
||
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||
<span class="kw">use</span> <span class="ident">tracing</span>::<span class="ident">info_span</span>;
|
||
|
||
<span class="comment">// Initially, let's assume that our attempt to do something is going okay...</span>
|
||
<span class="kw">let</span> <span class="ident">span</span> <span class="op">=</span> <span class="macro">info_span</span><span class="macro">!</span>(<span class="string">"doing_something"</span>, <span class="ident">is_okay</span> <span class="op">=</span> <span class="bool-val">true</span>);
|
||
<span class="kw">let</span> <span class="ident">_e</span> <span class="op">=</span> <span class="ident">span</span>.<span class="ident">enter</span>();
|
||
|
||
<span class="kw">match</span> <span class="ident">do_something</span>() {
|
||
<span class="prelude-val">Ok</span>(<span class="ident">something</span>) <span class="op">=</span><span class="op">></span> {
|
||
<span class="comment">// ...</span>
|
||
}
|
||
<span class="prelude-val">Err</span>(<span class="kw">_</span>) <span class="op">=</span><span class="op">></span> {
|
||
<span class="comment">// Things are no longer okay!</span>
|
||
<span class="ident">span</span>.<span class="ident">record</span>(<span class="string">"is_okay"</span>, <span class="kw-2">&</span><span class="bool-val">false</span>);
|
||
}
|
||
}</pre></div>
|
||
<div class="information">
|
||
<div class="tooltip ignore" style="">ⓘ<span class="tooltiptext">Note</span></div>
|
||
</div>
|
||
<div class="example-wrap" style="display:inline-block">
|
||
<pre class="ignore" style="white-space:normal;font:inherit;">
|
||
<strong>Note</strong>: The fields associated with a span are part of its
|
||
<a href="../struct.Metadata.html"><code>Metadata</code></a>.
|
||
The <a href="../struct.Metadata.html"><code>Metadata</code></a>. describing a particular
|
||
span is constructed statically when the span is created and cannot be extended later to
|
||
add new fields. Therefore, you cannot record a value for a field that was not specified
|
||
when the span was created:</pre></div>
|
||
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||
<span class="kw">use</span> <span class="ident">tracing</span>::{<span class="ident">trace_span</span>, <span class="ident">field</span>};
|
||
|
||
<span class="comment">// Create a span with two fields: `greeting`, with the value "hello world", and</span>
|
||
<span class="comment">// `parting`, without a value.</span>
|
||
<span class="kw">let</span> <span class="ident">span</span> <span class="op">=</span> <span class="macro">trace_span</span><span class="macro">!</span>(<span class="string">"my_span"</span>, <span class="ident">greeting</span> <span class="op">=</span> <span class="string">"hello world"</span>, <span class="ident">parting</span> <span class="op">=</span> <span class="ident">field</span>::<span class="ident">Empty</span>);
|
||
|
||
<span class="comment">// ...</span>
|
||
|
||
<span class="comment">// Now, you try to record a value for a new field, `new_field`, which was not</span>
|
||
<span class="comment">// declared as `Empty` or populated when you created `span`.</span>
|
||
<span class="comment">// You won't get any error, but the assignment will have no effect!</span>
|
||
<span class="ident">span</span>.<span class="ident">record</span>(<span class="string">"new_field"</span>, <span class="kw-2">&</span><span class="string">"interesting_value_you_really_need"</span>);
|
||
|
||
<span class="comment">// Instead, all fields that may be recorded after span creation should be declared up front,</span>
|
||
<span class="comment">// using field::Empty when a value is not known, as we did for `parting`.</span>
|
||
<span class="comment">// This `record` call will indeed replace field::Empty with "you will be remembered".</span>
|
||
<span class="ident">span</span>.<span class="ident">record</span>(<span class="string">"parting"</span>, <span class="kw-2">&</span><span class="string">"you will be remembered"</span>);</pre></div>
|
||
</div><h4 id="method.record_all" class="method"><code>pub fn <a href="#method.record_all" class="fnname">record_all</a>(&self, values: &<a class="struct" href="../../tracing/field/struct.ValueSet.html" title="struct tracing::field::ValueSet">ValueSet</a><'_>) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&</a>Self</code><a class="srclink" href="../../src/tracing/span.rs.html#1095-1113" title="goto source code">[src]</a></h4><div class="docblock"><p>Records all the fields in the provided <code>ValueSet</code>.</p>
|
||
</div><h4 id="method.is_disabled" class="method"><code>pub fn <a href="#method.is_disabled" class="fnname">is_disabled</a>(&self) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a></code><a class="srclink" href="../../src/tracing/span.rs.html#1122-1124" title="goto source code">[src]</a></h4><div class="docblock"><p>Returns <code>true</code> if this span was disabled by the subscriber and does not
|
||
exist.</p>
|
||
<p>See also <a href="#method.is_none"><code>is_none</code></a>.</p>
|
||
</div><h4 id="method.is_none" class="method"><code>pub fn <a href="#method.is_none" class="fnname">is_none</a>(&self) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a></code><a class="srclink" href="../../src/tracing/span.rs.html#1137-1139" title="goto source code">[src]</a></h4><div class="docblock"><p>Returns <code>true</code> if this span was constructed by <a href="#method.none"><code>Span::none</code></a> and is
|
||
empty.</p>
|
||
<p>If <code>is_none</code> returns <code>true</code> for a given span, then <a href="#method.is_disabled"><code>is_disabled</code></a> will
|
||
also return <code>true</code>. However, when a span is disabled by the subscriber
|
||
rather than constructed by <code>Span::none</code>, this method will return
|
||
<code>false</code>, while <code>is_disabled</code> will return <code>true</code>.</p>
|
||
</div><h4 id="method.follows_from" class="method"><code>pub fn <a href="#method.follows_from" class="fnname">follows_from</a>(&self, from: impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.Into.html" title="trait core::convert::Into">Into</a><<a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a><<a class="struct" href="../../tracing/span/struct.Id.html" title="struct tracing::span::Id">Id</a>>>) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&</a>Self</code><a class="srclink" href="../../src/tracing/span.rs.html#1188-1195" title="goto source code">[src]</a></h4><div class="docblock"><p>Indicates that the span with the given ID has an indirect causal
|
||
relationship with this span.</p>
|
||
<p>This relationship differs somewhat from the parent-child relationship: a
|
||
span may have any number of prior spans, rather than a single one; and
|
||
spans are not considered to be executing <em>inside</em> of the spans they
|
||
follow from. This means that a span may close even if subsequent spans
|
||
that follow from it are still open, and time spent inside of a
|
||
subsequent span should not be included in the time its precedents were
|
||
executing. This is used to model causal relationships such as when a
|
||
single future spawns several related background tasks, et cetera.</p>
|
||
<p>If this span is disabled, or the resulting follows-from relationship
|
||
would be invalid, this function will do nothing.</p>
|
||
<h1 id="examples-2" class="section-header"><a href="#examples-2">Examples</a></h1>
|
||
<p>Setting a <code>follows_from</code> relationship with a <code>Span</code>:</p>
|
||
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||
<span class="kw">let</span> <span class="ident">span1</span> <span class="op">=</span> <span class="macro">span</span><span class="macro">!</span>(<span class="ident">Level</span>::<span class="ident">INFO</span>, <span class="string">"span_1"</span>);
|
||
<span class="kw">let</span> <span class="ident">span2</span> <span class="op">=</span> <span class="macro">span</span><span class="macro">!</span>(<span class="ident">Level</span>::<span class="ident">DEBUG</span>, <span class="string">"span_2"</span>);
|
||
<span class="ident">span2</span>.<span class="ident">follows_from</span>(<span class="ident">span1</span>);</pre></div>
|
||
<p>Setting a <code>follows_from</code> relationship with the current span:</p>
|
||
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||
<span class="kw">let</span> <span class="ident">span</span> <span class="op">=</span> <span class="macro">span</span><span class="macro">!</span>(<span class="ident">Level</span>::<span class="ident">INFO</span>, <span class="string">"hello!"</span>);
|
||
<span class="ident">span</span>.<span class="ident">follows_from</span>(<span class="ident">Span</span>::<span class="ident">current</span>());</pre></div>
|
||
<p>Setting a <code>follows_from</code> relationship with a <code>Span</code> reference:</p>
|
||
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||
<span class="kw">let</span> <span class="ident">span</span> <span class="op">=</span> <span class="macro">span</span><span class="macro">!</span>(<span class="ident">Level</span>::<span class="ident">INFO</span>, <span class="string">"hello!"</span>);
|
||
<span class="kw">let</span> <span class="ident">curr</span> <span class="op">=</span> <span class="ident">Span</span>::<span class="ident">current</span>();
|
||
<span class="ident">span</span>.<span class="ident">follows_from</span>(<span class="kw-2">&</span><span class="ident">curr</span>);</pre></div>
|
||
<p>Setting a <code>follows_from</code> relationship with an <code>Id</code>:</p>
|
||
|
||
<div class="example-wrap"><pre class="rust rust-example-rendered">
|
||
<span class="kw">let</span> <span class="ident">span</span> <span class="op">=</span> <span class="macro">span</span><span class="macro">!</span>(<span class="ident">Level</span>::<span class="ident">INFO</span>, <span class="string">"hello!"</span>);
|
||
<span class="kw">let</span> <span class="ident">id</span> <span class="op">=</span> <span class="ident">span</span>.<span class="ident">id</span>();
|
||
<span class="ident">span</span>.<span class="ident">follows_from</span>(<span class="ident">id</span>);</pre></div>
|
||
</div><h4 id="method.id" class="method"><code>pub fn <a href="#method.id" class="fnname">id</a>(&self) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a><<a class="struct" href="../../tracing/span/struct.Id.html" title="struct tracing::span::Id">Id</a>></code><a class="srclink" href="../../src/tracing/span.rs.html#1198-1200" title="goto source code">[src]</a></h4><div class="docblock"><p>Returns this span's <code>Id</code>, if it is enabled.</p>
|
||
</div><h4 id="method.metadata" class="method"><code>pub fn <a href="#method.metadata" class="fnname">metadata</a>(&self) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a><&'static <a class="struct" href="../../tracing/struct.Metadata.html" title="struct tracing::Metadata">Metadata</a><'static>></code><a class="srclink" href="../../src/tracing/span.rs.html#1203-1205" title="goto source code">[src]</a></h4><div class="docblock"><p>Returns this span's <code>Metadata</code>, if it is enabled.</p>
|
||
</div><h4 id="method.with_subscriber" class="method"><code>pub fn <a href="#method.with_subscriber" class="fnname">with_subscriber</a><T>(<br> &self, <br> f: impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>(<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.tuple.html">(</a>&<a class="struct" href="../../tracing/span/struct.Id.html" title="struct tracing::span::Id">Id</a>, &<a class="struct" href="../../tracing/struct.Dispatch.html" title="struct tracing::Dispatch">Dispatch</a><a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.tuple.html">)</a>) -> T<br>) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a><T></code><a class="srclink" href="../../src/tracing/span.rs.html#1246-1250" title="goto source code">[src]</a></h4><div class="docblock"><p>Invokes a function with a reference to this span's ID and subscriber.</p>
|
||
<p>if this span is enabled, the provided function is called, and the result is returned.
|
||
If the span is disabled, the function is not called, and this method returns <code>None</code>
|
||
instead.</p>
|
||
</div></div><h2 id="trait-implementations" class="small-section-header">Trait Implementations<a href="#trait-implementations" class="anchor"></a></h2><div id="trait-implementations-list"><h3 id="impl-Debug" class="impl"><code class="in-band">impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/fmt/trait.Debug.html" title="trait core::fmt::Debug">Debug</a> for <a class="struct" href="../../tracing/span/struct.EnteredSpan.html" title="struct tracing::span::EnteredSpan">EnteredSpan</a></code><a href="#impl-Debug" class="anchor"></a><a class="srclink" href="../../src/tracing/span.rs.html#412" title="goto source code">[src]</a></h3><div class="impl-items"><h4 id="method.fmt" class="method hidden"><code>fn <a href="https://doc.rust-lang.org/nightly/core/fmt/trait.Debug.html#tymethod.fmt" class="fnname">fmt</a>(&self, f: &mut <a class="struct" href="https://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html" title="struct core::fmt::Formatter">Formatter</a><'_>) -> <a class="type" href="https://doc.rust-lang.org/nightly/core/fmt/type.Result.html" title="type core::fmt::Result">Result</a></code><a class="srclink" href="../../src/tracing/span.rs.html#412" title="goto source code">[src]</a></h4><div class='docblock hidden'><p>Formats the value using the given formatter. <a href="https://doc.rust-lang.org/nightly/core/fmt/trait.Debug.html#tymethod.fmt">Read more</a></p>
|
||
</div></div><h3 id="impl-Deref" class="impl"><code class="in-band">impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/deref/trait.Deref.html" title="trait core::ops::deref::Deref">Deref</a> for <a class="struct" href="../../tracing/span/struct.EnteredSpan.html" title="struct tracing::span::EnteredSpan">EnteredSpan</a></code><a href="#impl-Deref" class="anchor"></a><a class="srclink" href="../../src/tracing/span.rs.html#1416-1423" title="goto source code">[src]</a></h3><div class="impl-items"><h4 id="associatedtype.Target" class="type"><code>type <a href="https://doc.rust-lang.org/nightly/core/ops/deref/trait.Deref.html#associatedtype.Target" class="type">Target</a> = <a class="struct" href="../../tracing/struct.Span.html" title="struct tracing::Span">Span</a></code></h4><div class='docblock'><p>The resulting type after dereferencing.</p>
|
||
</div><h4 id="method.deref" class="method hidden"><code>fn <a href="https://doc.rust-lang.org/nightly/core/ops/deref/trait.Deref.html#tymethod.deref" class="fnname">deref</a>(&self) -> &<a class="struct" href="../../tracing/struct.Span.html" title="struct tracing::Span">Span</a></code><a class="srclink" href="../../src/tracing/span.rs.html#1420-1422" title="goto source code">[src]</a></h4><div class='docblock hidden'><p>Dereferences the value.</p>
|
||
</div></div><h3 id="impl-Drop" class="impl"><code class="in-band">impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/drop/trait.Drop.html" title="trait core::ops::drop::Drop">Drop</a> for <a class="struct" href="../../tracing/span/struct.EnteredSpan.html" title="struct tracing::span::EnteredSpan">EnteredSpan</a></code><a href="#impl-Drop" class="anchor"></a><a class="srclink" href="../../src/tracing/span.rs.html#1432-1437" title="goto source code">[src]</a></h3><div class="impl-items"><h4 id="method.drop" class="method hidden"><code>fn <a href="https://doc.rust-lang.org/nightly/core/ops/drop/trait.Drop.html#tymethod.drop" class="fnname">drop</a>(&mut self)</code><a class="srclink" href="../../src/tracing/span.rs.html#1434-1436" title="goto source code">[src]</a></h4><div class='docblock hidden'><p>Executes the destructor for this type. <a href="https://doc.rust-lang.org/nightly/core/ops/drop/trait.Drop.html#tymethod.drop">Read more</a></p>
|
||
</div></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"><h3 id="impl-RefUnwindSafe" class="impl"><code class="in-band">impl !<a class="trait" href="https://doc.rust-lang.org/nightly/std/panic/trait.RefUnwindSafe.html" title="trait std::panic::RefUnwindSafe">RefUnwindSafe</a> for <a class="struct" href="../../tracing/span/struct.EnteredSpan.html" title="struct tracing::span::EnteredSpan">EnteredSpan</a></code><a href="#impl-RefUnwindSafe" class="anchor"></a><a class="srclink" href="../../src/tracing/lib.rs.html#1" title="goto source code">[src]</a></h3><div class="impl-items"></div><h3 id="impl-Send" class="impl"><code class="in-band">impl !<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a> for <a class="struct" href="../../tracing/span/struct.EnteredSpan.html" title="struct tracing::span::EnteredSpan">EnteredSpan</a></code><a href="#impl-Send" class="anchor"></a><a class="srclink" href="../../src/tracing/lib.rs.html#1" title="goto source code">[src]</a></h3><div class="impl-items"></div><h3 id="impl-Sync" class="impl"><code class="in-band">impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sync.html" title="trait core::marker::Sync">Sync</a> for <a class="struct" href="../../tracing/span/struct.EnteredSpan.html" title="struct tracing::span::EnteredSpan">EnteredSpan</a></code><a href="#impl-Sync" class="anchor"></a><a class="srclink" href="../../src/tracing/lib.rs.html#1" title="goto source code">[src]</a></h3><div class="impl-items"></div><h3 id="impl-Unpin" class="impl"><code class="in-band">impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Unpin.html" title="trait core::marker::Unpin">Unpin</a> for <a class="struct" href="../../tracing/span/struct.EnteredSpan.html" title="struct tracing::span::EnteredSpan">EnteredSpan</a></code><a href="#impl-Unpin" class="anchor"></a><a class="srclink" href="../../src/tracing/lib.rs.html#1" title="goto source code">[src]</a></h3><div class="impl-items"></div><h3 id="impl-UnwindSafe" class="impl"><code class="in-band">impl !<a class="trait" href="https://doc.rust-lang.org/nightly/std/panic/trait.UnwindSafe.html" title="trait std::panic::UnwindSafe">UnwindSafe</a> for <a class="struct" href="../../tracing/span/struct.EnteredSpan.html" title="struct tracing::span::EnteredSpan">EnteredSpan</a></code><a href="#impl-UnwindSafe" class="anchor"></a><a class="srclink" href="../../src/tracing/lib.rs.html#1" title="goto source code">[src]</a></h3><div class="impl-items"></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"><h3 id="impl-Any" class="impl"><code class="in-band">impl<T> <a class="trait" href="https://doc.rust-lang.org/nightly/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/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>, </span></code><a href="#impl-Any" class="anchor"></a><a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/any.rs.html#131-135" title="goto source code">[src]</a></h3><div class="impl-items"><h4 id="method.type_id" class="method hidden"><code>pub fn <a href="https://doc.rust-lang.org/nightly/core/any/trait.Any.html#tymethod.type_id" class="fnname">type_id</a>(&self) -> <a class="struct" href="https://doc.rust-lang.org/nightly/core/any/struct.TypeId.html" title="struct core::any::TypeId">TypeId</a></code><a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/any.rs.html#132" title="goto source code">[src]</a></h4><div class='docblock hidden'><p>Gets the <code>TypeId</code> of <code>self</code>. <a href="https://doc.rust-lang.org/nightly/core/any/trait.Any.html#tymethod.type_id">Read more</a></p>
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</div></div><h3 id="impl-Borrow%3CT%3E" class="impl"><code class="in-band">impl<T> <a class="trait" href="https://doc.rust-lang.org/nightly/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/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>, </span></code><a href="#impl-Borrow%3CT%3E" class="anchor"></a><a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#207-211" title="goto source code">[src]</a></h3><div class="impl-items"><h4 id="method.borrow" class="method hidden"><code>pub fn <a href="https://doc.rust-lang.org/nightly/core/borrow/trait.Borrow.html#tymethod.borrow" class="fnname">borrow</a>(&self) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&</a>T</code><a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#208" title="goto source code">[src]</a></h4><div class='docblock hidden'><p>Immutably borrows from an owned value. <a href="https://doc.rust-lang.org/nightly/core/borrow/trait.Borrow.html#tymethod.borrow">Read more</a></p>
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</div></div><h3 id="impl-BorrowMut%3CT%3E" class="impl"><code class="in-band">impl<T> <a class="trait" href="https://doc.rust-lang.org/nightly/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/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>, </span></code><a href="#impl-BorrowMut%3CT%3E" class="anchor"></a><a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#214-218" title="goto source code">[src]</a></h3><div class="impl-items"><h4 id="method.borrow_mut" class="method hidden"><code>pub fn <a href="https://doc.rust-lang.org/nightly/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut" class="fnname">borrow_mut</a>(&mut self) -> <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&mut </a>T</code><a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/borrow.rs.html#215" title="goto source code">[src]</a></h4><div class='docblock hidden'><p>Mutably borrows from an owned value. <a href="https://doc.rust-lang.org/nightly/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut">Read more</a></p>
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</div></div><h3 id="impl-From%3CT%3E" class="impl"><code class="in-band">impl<T> <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html" title="trait core::convert::From">From</a><T> for T</code><a href="#impl-From%3CT%3E" class="anchor"></a><a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#545-549" title="goto source code">[src]</a></h3><div class="impl-items"><h4 id="method.from" class="method hidden"><code>pub fn <a href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html#tymethod.from" class="fnname">from</a>(t: T) -> T</code><a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#546" title="goto source code">[src]</a></h4><div class='docblock hidden'><p>Performs the conversion.</p>
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||
</div></div><h3 id="impl-Instrument" class="impl"><code class="in-band">impl<T> <a class="trait" href="../../tracing/trait.Instrument.html" title="trait tracing::Instrument">Instrument</a> for T</code><a href="#impl-Instrument" class="anchor"></a><a class="srclink" href="../../src/tracing/instrument.rs.html#155" title="goto source code">[src]</a></h3><div class="impl-items"><h4 id="method.instrument" class="method hidden"><code>fn <a href="../../tracing/trait.Instrument.html#method.instrument" class="fnname">instrument</a>(self, span: <a class="struct" href="../../tracing/struct.Span.html" title="struct tracing::Span">Span</a>) -> <a class="struct" href="../../tracing/instrument/struct.Instrumented.html" title="struct tracing::instrument::Instrumented">Instrumented</a><Self><span class="notable-traits"><span class="notable-traits-tooltip">ⓘ<div class="notable-traits-tooltiptext"><span class="docblock"><h3 class="notable">Notable traits for <a class="struct" href="../../tracing/instrument/struct.Instrumented.html" title="struct tracing::instrument::Instrumented">Instrumented</a><T></h3><code class="content"><span class="where fmt-newline">impl<T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/future/future/trait.Future.html" title="trait core::future::future::Future">Future</a>> <a class="trait" href="https://doc.rust-lang.org/nightly/core/future/future/trait.Future.html" title="trait core::future::future::Future">Future</a> for <a class="struct" href="../../tracing/instrument/struct.Instrumented.html" title="struct tracing::instrument::Instrumented">Instrumented</a><T></span><span class="where fmt-newline"> type <a href="https://doc.rust-lang.org/nightly/core/future/future/trait.Future.html#associatedtype.Output" class="type">Output</a> = T::<a class="type" href="https://doc.rust-lang.org/nightly/core/future/future/trait.Future.html#associatedtype.Output" title="type core::future::future::Future::Output">Output</a>;</span></code></span></div></span></span></code><a class="srclink" href="../../src/tracing/instrument.rs.html#38-40" title="goto source code">[src]</a></h4><div class='docblock hidden'><p>Instruments this type with the provided <code>Span</code>, returning an
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<code>Instrumented</code> wrapper. <a href="../../tracing/trait.Instrument.html#method.instrument">Read more</a></p>
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</div><h4 id="method.in_current_span" class="method hidden"><code>fn <a href="../../tracing/trait.Instrument.html#method.in_current_span" class="fnname">in_current_span</a>(self) -> <a class="struct" href="../../tracing/instrument/struct.Instrumented.html" title="struct tracing::instrument::Instrumented">Instrumented</a><Self><span class="notable-traits"><span class="notable-traits-tooltip">ⓘ<div class="notable-traits-tooltiptext"><span class="docblock"><h3 class="notable">Notable traits for <a class="struct" href="../../tracing/instrument/struct.Instrumented.html" title="struct tracing::instrument::Instrumented">Instrumented</a><T></h3><code class="content"><span class="where fmt-newline">impl<T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/future/future/trait.Future.html" title="trait core::future::future::Future">Future</a>> <a class="trait" href="https://doc.rust-lang.org/nightly/core/future/future/trait.Future.html" title="trait core::future::future::Future">Future</a> for <a class="struct" href="../../tracing/instrument/struct.Instrumented.html" title="struct tracing::instrument::Instrumented">Instrumented</a><T></span><span class="where fmt-newline"> type <a href="https://doc.rust-lang.org/nightly/core/future/future/trait.Future.html#associatedtype.Output" class="type">Output</a> = T::<a class="type" href="https://doc.rust-lang.org/nightly/core/future/future/trait.Future.html#associatedtype.Output" title="type core::future::future::Future::Output">Output</a>;</span></code></span></div></span></span></code><a class="srclink" href="../../src/tracing/instrument.rs.html#74-76" title="goto source code">[src]</a></h4><div class='docblock hidden'><p>Instruments this type with the <a href="../struct.Span.html#method.current">current</a> <code>Span</code>, returning an
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<code>Instrumented</code> wrapper. <a href="../../tracing/trait.Instrument.html#method.in_current_span">Read more</a></p>
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</div></div><h3 id="impl-Into%3CU%3E" class="impl"><code class="in-band">impl<T, U> <a class="trait" href="https://doc.rust-lang.org/nightly/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/nightly/core/convert/trait.From.html" title="trait core::convert::From">From</a><T>, </span></code><a href="#impl-Into%3CU%3E" class="anchor"></a><a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#534-541" title="goto source code">[src]</a></h3><div class="impl-items"><h4 id="method.into" class="method hidden"><code>pub fn <a href="https://doc.rust-lang.org/nightly/core/convert/trait.Into.html#tymethod.into" class="fnname">into</a>(self) -> U</code><a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#538" title="goto source code">[src]</a></h4><div class='docblock hidden'><p>Performs the conversion.</p>
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</div></div><h3 id="impl-TryFrom%3CU%3E" class="impl"><code class="in-band">impl<T, U> <a class="trait" href="https://doc.rust-lang.org/nightly/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/nightly/core/convert/trait.Into.html" title="trait core::convert::Into">Into</a><T>, </span></code><a href="#impl-TryFrom%3CU%3E" class="anchor"></a><a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#582-591" title="goto source code">[src]</a></h3><div class="impl-items"><h4 id="associatedtype.Error" class="type"><code>type <a href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#associatedtype.Error" class="type">Error</a> = <a class="enum" href="https://doc.rust-lang.org/nightly/core/convert/enum.Infallible.html" title="enum core::convert::Infallible">Infallible</a></code></h4><div class='docblock'><p>The type returned in the event of a conversion error.</p>
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</div><h4 id="method.try_from" class="method hidden"><code>pub fn <a href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#tymethod.try_from" class="fnname">try_from</a>(value: U) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><T, <T as <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><U>>::<a class="type" href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a>></code><a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#588" title="goto source code">[src]</a></h4><div class='docblock hidden'><p>Performs the conversion.</p>
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</div></div><h3 id="impl-TryInto%3CU%3E" class="impl"><code class="in-band">impl<T, U> <a class="trait" href="https://doc.rust-lang.org/nightly/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/nightly/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><T>, </span></code><a href="#impl-TryInto%3CU%3E" class="anchor"></a><a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#568-577" title="goto source code">[src]</a></h3><div class="impl-items"><h4 id="associatedtype.Error-1" class="type"><code>type <a href="https://doc.rust-lang.org/nightly/core/convert/trait.TryInto.html#associatedtype.Error" class="type">Error</a> = <U as <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><T>>::<a class="type" href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a></code></h4><div class='docblock'><p>The type returned in the event of a conversion error.</p>
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</div><h4 id="method.try_into" class="method hidden"><code>pub fn <a href="https://doc.rust-lang.org/nightly/core/convert/trait.TryInto.html#tymethod.try_into" class="fnname">try_into</a>(self) -> <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a><U, <U as <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html" title="trait core::convert::TryFrom">TryFrom</a><T>>::<a class="type" href="https://doc.rust-lang.org/nightly/core/convert/trait.TryFrom.html#associatedtype.Error" title="type core::convert::TryFrom::Error">Error</a>></code><a class="srclink" href="https://doc.rust-lang.org/nightly/src/core/convert/mod.rs.html#574" title="goto source code">[src]</a></h4><div class='docblock hidden'><p>Performs the conversion.</p>
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