<main><divclass="width-limiter"><navclass="sub"><formclass="search-form"><span></span><divid="sidebar-button"tabindex="-1"><ahref="../../tracing_core/all.html"title="show sidebar"></a></div><inputclass="search-input"name="search"aria-label="Run search in the documentation"autocomplete="off"spellcheck="false"placeholder="Click or press ‘S’ to search, ‘?’ for more options…"type="search"><divid="help-button"tabindex="-1"><ahref="../../help.html"title="help">?</a></div><divid="settings-menu"tabindex="-1"><ahref="../../settings.html"title="settings"><imgwidth="22"height="22"alt="Change settings"src="../../static.files/wheel-7b819b6101059cd0.svg"></a></div></form></nav><sectionid="main-content"class="content"><divclass="main-heading"><h1>Struct <ahref="../index.html">tracing_core</a>::<wbr><ahref="index.html">event</a>::<wbr><aclass="struct"href="#">Event</a><buttonid="copy-path"title="Copy item path to clipboard"><imgsrc="../../static.files/clipboard-7571035ce49a181d.svg"width="19"height="18"alt="Copy item path"></button></h1><spanclass="out-of-band"><aclass="src"href="../../src/tracing_core/event.rs.html#23-27">source</a> · <buttonid="toggle-all-docs"title="collapse all docs">[<span>−</span>]</button></span></div><preclass="rust item-decl"><code>pub struct Event<'a> { <spanclass="comment">/* private fields */</span> }</code></pre><detailsclass="toggle top-doc"open><summaryclass="hideme"><span>Expand description</span></summary><divclass="docblock"><p><code>Event</code>s represent single points in time where something occurred during the
execution of a program.</p>
<p>An <code>Event</code> can be compared to a log record in unstructured logging, but with
two key differences:</p>
<ul>
<li><code>Event</code>s exist <em>within the context of a <ahref="../span/index.html"title="mod tracing_core::span">span</a></em>. Unlike log lines, they
may be located within the trace tree, allowing visibility into the
<em>temporal</em> context in which the event occurred, as well as the source
code location.</li>
<li>Like spans, <code>Event</code>s have structured key-value data known as <em><ahref="../field/index.html"title="mod tracing_core::field">fields</a></em>,
which may include textual message. In general, a majority of the data
associated with an event should be in the event’s fields rather than in
the textual message, as the fields are more structured.</li>
</ul>
</div></details><h2id="implementations"class="section-header">Implementations<ahref="#implementations"class="anchor">§</a></h2><divid="implementations-list"><detailsclass="toggle implementors-toggle"open><summary><sectionid="impl-Event%3C'a%3E"class="impl"><aclass="src rightside"href="../../src/tracing_core/event.rs.html#29-128">source</a><ahref="#impl-Event%3C'a%3E"class="anchor">§</a><h3class="code-header">impl<'a><aclass="struct"href="../struct.Event.html"title="struct tracing_core::Event">Event</a><'a></h3></section></summary><divclass="impl-items"><detailsclass="toggle method-toggle"open><summary><sectionid="method.dispatch"class="method"><aclass="src rightside"href="../../src/tracing_core/event.rs.html#32-37">source</a><h4class="code-header">pub fn <ahref="#method.dispatch"class="fn">dispatch</a>(metadata: &'static <aclass="struct"href="../struct.Metadata.html"title="struct tracing_core::Metadata">Metadata</a><'static>, fields: &'a <aclass="struct"href="../field/struct.ValueSet.html"title="struct tracing_core::field::ValueSet">ValueSet</a><'_>)</h4></section></summary><divclass="docblock"><p>Constructs a new <code>Event</code> with the specified metadata and set of values,
)</h4></section></summary><divclass="docblock"><p>Constructs a new <code>Event</code> with the specified metadata and set of values,
and observes it with the current subscriber and an explicit parent.</p>
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.record"class="method"><aclass="src rightside"href="../../src/tracing_core/event.rs.html#86-88">source</a><h4class="code-header">pub fn <ahref="#method.record"class="fn">record</a>(&self, visitor: &mut dyn <aclass="trait"href="../field/trait.Visit.html"title="trait tracing_core::field::Visit">Visit</a>)</h4></section></summary><divclass="docblock"><p>Visits all the fields on this <code>Event</code> with the specified <ahref="../field/trait.Visit.html"title="trait tracing_core::field::Visit">visitor</a>.</p>
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.fields"class="method"><aclass="src rightside"href="../../src/tracing_core/event.rs.html#91-93">source</a><h4class="code-header">pub fn <ahref="#method.fields"class="fn">fields</a>(&self) -><aclass="struct"href="../field/struct.Iter.html"title="struct tracing_core::field::Iter">Iter</a><ahref="#"class="tooltip"data-notable-ty="Iter">ⓘ</a></h4></section></summary><divclass="docblock"><p>Returns an iterator over the set of values on this <code>Event</code>.</p>
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.is_root"class="method"><aclass="src rightside"href="../../src/tracing_core/event.rs.html#103-105">source</a><h4class="code-header">pub fn <ahref="#method.is_root"class="fn">is_root</a>(&self) -><aclass="primitive"href="https://doc.rust-lang.org/1.78.0/std/primitive.bool.html">bool</a></h4></section></summary><divclass="docblock"><p>Returns true if the new event should be a root.</p>
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.is_contextual"class="method"><aclass="src rightside"href="../../src/tracing_core/event.rs.html#114-116">source</a><h4class="code-header">pub fn <ahref="#method.is_contextual"class="fn">is_contextual</a>(&self) -><aclass="primitive"href="https://doc.rust-lang.org/1.78.0/std/primitive.bool.html">bool</a></h4></section></summary><divclass="docblock"><p>Returns true if the new event’s parent should be determined based on the
</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.parent"class="method"><aclass="src rightside"href="../../src/tracing_core/event.rs.html#122-127">source</a><h4class="code-header">pub fn <ahref="#method.parent"class="fn">parent</a>(&self) -><aclass="enum"href="https://doc.rust-lang.org/1.78.0/core/option/enum.Option.html"title="enum core::option::Option">Option</a><&<aclass="struct"href="../span/struct.Id.html"title="struct tracing_core::span::Id">Id</a>></h4></section></summary><divclass="docblock"><p>Returns the new event’s explicitly-specified parent, if there is one.</p>
</div></details></div></details></div><h2id="trait-implementations"class="section-header">Trait Implementations<ahref="#trait-implementations"class="anchor">§</a></h2><divid="trait-implementations-list"><detailsclass="toggle implementors-toggle"open><summary><sectionid="impl-Debug-for-Event%3C'a%3E"class="impl"><aclass="src rightside"href="../../src/tracing_core/event.rs.html#22">source</a><ahref="#impl-Debug-for-Event%3C'a%3E"class="anchor">§</a><h3class="code-header">impl<'a><aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/fmt/trait.Debug.html"title="trait core::fmt::Debug">Debug</a> for <aclass="struct"href="../struct.Event.html"title="struct tracing_core::Event">Event</a><'a></h3></section></summary><divclass="impl-items"><detailsclass="toggle method-toggle"open><summary><sectionid="method.fmt"class="method trait-impl"><aclass="src rightside"href="../../src/tracing_core/event.rs.html#22">source</a><ahref="#method.fmt"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.78.0/core/fmt/trait.Debug.html#tymethod.fmt"class="fn">fmt</a>(&self, f: &mut <aclass="struct"href="https://doc.rust-lang.org/1.78.0/core/fmt/struct.Formatter.html"title="struct core::fmt::Formatter">Formatter</a><'_>) -><aclass="type"href="https://doc.rust-lang.org/1.78.0/core/fmt/type.Result.html"title="type core::fmt::Result">Result</a></h4></section></summary><divclass='docblock'>Formats the value using the given formatter. <ahref="https://doc.rust-lang.org/1.78.0/core/fmt/trait.Debug.html#tymethod.fmt">Read more</a></div></details></div></details></div><h2id="synthetic-implementations"class="section-header">Auto Trait Implementations<ahref="#synthetic-implementations"class="anchor">§</a></h2><divid="synthetic-implementations-list"><sectionid="impl-Freeze-for-Event%3C'a%3E"class="impl"><ahref="#impl-Freeze-for-Event%3C'a%3E"class="anchor">§</a><h3class="code-header">impl<'a><aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/marker/trait.Freeze.html"title="trait core::marker::Freeze">Freeze</a> for <aclass="struct"href="../struct.Event.html"title="struct tracing_core::Event">Event</a><'a></h3></section><sectionid="impl-RefUnwindSafe-for-Event%3C'a%3E"class="impl"><ahref="#impl-RefUnwindSafe-for-Event%3C'a%3E"class="anchor">§</a><h3class="code-header">impl<'a> !<aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/panic/unwind_safe/trait.RefUnwindSafe.html"title="trait core::panic::unwind_safe::RefUnwindSafe">RefUnwindSafe</a> for <aclass="struct"href="../struct.Event.html"title="struct tracing_core::Event">Event</a><'a></h3></section><sectionid="impl-Send-for-Event%3C'a%3E"class="impl"><ahref="#impl-Send-for-Event%3C'a%3E"class="anchor">§</a><h3class="code-header">impl<'a> !<aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/marker/trait.Send.html"title="trait core::marker::Send">Send</a> for <aclass="struct"href="../struct.Event.html"title="struct tracing_core::Event">Event</a><'a></h3></section><sectionid="impl-Sync-for-Event%3C'a%3E"class="impl"><ahref="#impl-Sync-for-Event%3C'a%3E"class="anchor">§</a><h3class="code-header">impl<'a> !<aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/marker/trait.Sync.html"title="trait core::marker::Sync">Sync</a> for <aclass="struct"href="../struct.Event.html"title="struct tracing_core::Event">Event</a><'a></h3></section><sectionid="impl-Unpin-for-Event%3C'a%3E"class="impl"><ahref="#impl-Unpin-for-Event%3C'a%3E"class="anchor">§</a><h3class="code-header">impl<'a><aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/marker/trait.Unpin.html"title="trait core::marker::Unpin">Unpin</a> for <aclass="struct"href="../struct.Event.html"title="struct tracing_core::Event">Event</a><'a></h3></section><sectionid="impl-UnwindSafe-for-Event%3C'a%3E"class="impl"><ahref="#impl-UnwindSafe-for-Event%3C'a%3E"class="anchor">§</a><h3class="code-header">impl&
T: 'static + ?<aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle method-toggle"open><summary><sectionid="method.type_id"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.78.0/src/core/any.rs.html#141">source</a><ahref="#method.type_id"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.78.0/core/any/trait.Any.html#tymethod.type_id"class="fn">type_id</a>(&self) -><aclass="struct"href="https://doc.rust-lang.org/1.78.0/core/any/struct.TypeId.html"title="struct core::any::TypeId">TypeId</a></h4></section></summary><divclass='docblock'>Gets the <code>TypeId</code> of <code>self</code>. <ahref="https://doc.rust-lang.org/1.78.0/core/any/trait.Any.html#tymethod.type_id">Read more</a></div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-Borrow%3CT%3E-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.78.0/src/core/borrow.rs.html#208">source</a><ahref="#impl-Borrow%3CT%3E-for-T"class="anchor">§</a><h3class="code-header">impl<T><aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/borrow/trait.Borrow.html"title="trait core::borrow::Borrow">Borrow</a><T> for T<divclass="where">where
T: ?<aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle method-toggle"open><summary><sectionid="method.borrow"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.78.0/src/core/borrow.rs.html#210">source</a><ahref="#method.borrow"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.78.0/core/borrow/trait.Borrow.html#tymethod.borrow"class="fn">borrow</a>(&self) -><aclass="primitive"href="https://doc.rust-lang.org/1.78.0/std/primitive.reference.html">&T</a></h4></section></summary><divclass='docblock'>Immutably borrows from an owned value. <ahref="https://doc.rust-lang.org/1.78.0/core/borrow/trait.Borrow.html#tymethod.borrow">Read more</a></div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-BorrowMut%3CT%3E-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.78.0/src/core/borrow.rs.html#216">source</a><ahref="#impl-BorrowMut%3CT%3E-for-T"class="anchor">§</a><h3class="code-header">impl<T><aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/borrow/trait.BorrowMut.html"title="trait core::borrow::BorrowMut">BorrowMut</a><T> for T<divclass="where">where
T: ?<aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/marker/trait.Sized.html"title="trait core::marker::Sized">Sized</a>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle method-toggle"open><summary><sectionid="method.borrow_mut"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.78.0/src/core/borrow.rs.html#217">source</a><ahref="#method.borrow_mut"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.78.0/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut"class="fn">borrow_mut</a>(&mut self) -><aclass="primitive"href="https://doc.rust-lang.org/1.78.0/std/primitive.reference.html">&mut T</a></h4></section></summary><divclass='docblock'>Mutably borrows from an owned value. <ahref="https://doc.rust-lang.org/1.78.0/core/borrow/trait.BorrowMut.html#tymethod.borrow_mut">Read more</a></div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-From%3CT%3E-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.78.0/src/core/convert/mod.rs.html#765">source</a><ahref="#impl-From%3CT%3E-for-T"class="anchor">§</a><h3class="code-header">impl<T><aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/convert/trait.From.html"title="trait core::convert::From">From</a><T> for T</h3></section></summary><divclass="impl-items"><detailsclass="toggle method-toggle"open><summary><sectionid="method.from"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.78.0/src/core/convert/mod.rs.html#768">source</a><ahref="#method.from"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.78.0/core/convert/trait.From.html#tymethod.from"class="fn">from</a>(t: T) -> T</h4></section></summary><divclass="docblock"><p>Returns the argument unchanged.</p>
</div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-Into%3CU%3E-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.78.0/src/core/convert/mod.rs.html#748-750">source</a><ahref="#impl-Into%3CU%3E-for-T"class="anchor">§</a><h3class="code-header">impl<T, U><aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/convert/trait.Into.html"title="trait core::convert::Into">Into</a><U> for T<divclass="where">where
<code><ahref="https://doc.rust-lang.org/1.78.0/core/convert/trait.From.html"title="trait core::convert::From">From</a><T> for U</code> chooses to do.</p>
</div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-TryFrom%3CU%3E-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.78.0/src/core/convert/mod.rs.html#805-807">source</a><ahref="#impl-TryFrom%3CU%3E-for-T"class="anchor">§</a><h3class="code-header">impl<T, U><aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><U> for T<divclass="where">where
U: <aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/convert/trait.Into.html"title="trait core::convert::Into">Into</a><T>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle"open><summary><sectionid="associatedtype.Error-1"class="associatedtype trait-impl"><ahref="#associatedtype.Error-1"class="anchor">§</a><h4class="code-header">type <ahref="https://doc.rust-lang.org/1.78.0/core/convert/trait.TryFrom.html#associatedtype.Error"class="associatedtype">Error</a> = <aclass="enum"href="https://doc.rust-lang.org/1.78.0/core/convert/enum.Infallible.html"title="enum core::convert::Infallible">Infallible</a></h4></section></summary><divclass='docblock'>The type returned in the event of a conversion error.</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.try_from"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.78.0/src/core/convert/mod.rs.html#812">source</a><ahref="#method.try_from"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.78.0/core/convert/trait.TryFrom.html#tymethod.try_from"class="fn">try_from</a>(value: U) -><aclass="enum"href="https://doc.rust-lang.org/1.78.0/core/result/enum.Result.html"title="enum core::result::Result">Result</a><T, <T as <aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><U>>::<aclass="associatedtype"href="https://doc.rust-lang.org/1.78.0/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a>></h4></section></summary><divclass='docblock'>Performs the conversion.</div></details></div></details><detailsclass="toggle implementors-toggle"><summary><sectionid="impl-TryInto%3CU%3E-for-T"class="impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.78.0/src/core/convert/mod.rs.html#790-792">source</a><ahref="#impl-TryInto%3CU%3E-for-T"class="anchor">§</a><h3class="code-header">impl<T, U><aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/convert/trait.TryInto.html"title="trait core::convert::TryInto">TryInto</a><U> for T<divclass="where">where
U: <aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>,</div></h3></section></summary><divclass="impl-items"><detailsclass="toggle"open><summary><sectionid="associatedtype.Error"class="associatedtype trait-impl"><ahref="#associatedtype.Error"class="anchor">§</a><h4class="code-header">type <ahref="https://doc.rust-lang.org/1.78.0/core/convert/trait.TryInto.html#associatedtype.Error"class="associatedtype">Error</a> = <U as <aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>>::<aclass="associatedtype"href="https://doc.rust-lang.org/1.78.0/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a></h4></section></summary><divclass='docblock'>The type returned in the event of a conversion error.</div></details><detailsclass="toggle method-toggle"open><summary><sectionid="method.try_into"class="method trait-impl"><aclass="src rightside"href="https://doc.rust-lang.org/1.78.0/src/core/convert/mod.rs.html#797">source</a><ahref="#method.try_into"class="anchor">§</a><h4class="code-header">fn <ahref="https://doc.rust-lang.org/1.78.0/core/convert/trait.TryInto.html#tymethod.try_into"class="fn">try_into</a>(self) -><aclass="enum"href="https://doc.rust-lang.org/1.78.0/core/result/enum.Result.html"title="enum core::result::Result">Result</a><U, <U as <aclass="trait"href="https://doc.rust-lang.org/1.78.0/core/convert/trait.TryFrom.html"title="trait core::convert::TryFrom">TryFrom</a><T>>::<aclass="associatedtype"href="https://doc.rust-lang.org/1.78.0/core/convert/trait.TryFrom.html#associatedtype.Error"title="type core::convert::TryFrom::Error">Error</a>></h4></section></summary><divclass='docblock'>Performs the conversion.</div></details></div></details></div><scripttype="text/json"id="notable-traits-data">{"Iter":"<h3>Notable traits for <code><a class=\"struct\" href=\"../field/struct.Iter.html\" title=\"struct tracing_core::field::Iter\">Iter</a></code></h3><pre><code><div class=\"where\">impl <a class=\"trait\" href=\"https://doc.rust-lang.org/1.78.0/core/iter/traits/iterator/trait.Iterator.html\" title=\"trait core::iter::traits::iterator::Iterator\">Iterator</a> for <a class=\"struct\" href=\"../field/struct.Iter.html\" title=\"struct tracing_core::field::Iter\">Iter</a></div><div class=\"where\"> type <a href=\"https://doc.rust-lang.org/1.78.0/core/iter/traits/iterator/trait.Iterator.html#associatedtype.Item\" class=\"associatedtype\">Item</a> = <a class=\"struct\" href=\"../struct.Field.html\" title=\"struct tracing_core::Field\">Field</a>;</div>"}</script></section></div></main></body></html>
