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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="Logs a message at the trace level."><meta name="keywords" content="rust, rustlang, rust-lang, trace"><title>trace in log - Rust</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" type="text/css" href="../normalize.css"><link rel="stylesheet" type="text/css" href="../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../ayu.css" disabled><link rel="stylesheet" type="text/css" href="../dark.css" disabled><link rel="stylesheet" type="text/css" href="../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../storage.js"></script><script src="../crates.js"></script><script defer src="../main.js"></script>
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</a><div class="sidebar-elems"><h2 class="location"><a href="index.html">In log</a></h2><div id="sidebar-vars" data-name="trace" data-ty="macro" data-relpath=""></div><script defer src="sidebar-items.js"></script></div></nav><main><div class="width-limiter"><div class="sub-container"><a class="sub-logo-container" href="../log/index.html">
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<h1 class="fqn"><span class="in-band">Macro <a href="index.html">log</a>::<wbr><a class="macro" href="#">trace</a><button id="copy-path" onclick="copy_path(this)" title="Copy item path to clipboard"><img src="../clipboard.svg" width="19" height="18" alt="Copy item path"></button></span></h1><span class="out-of-band"><a class="srclink" href="../src/log/macros.rs.html#179-186">source</a> · <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class="inner">&#x2212;</span>]</a></span></div><div class="docblock item-decl"><div class="example-wrap"><pre class="rust macro"><code><span class="macro">macro_rules!</span> <span class="ident">trace</span> {
(<span class="ident">target</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">target</span>:<span class="ident">expr</span>, $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>:<span class="ident">tt</span>)<span class="op">+</span>) =&gt; { ... };
($(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">arg</span>:<span class="ident">tt</span>)<span class="op">+</span>) =&gt; { ... };
}</code></pre></div>
</div><details class="rustdoc-toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Logs a message at the trace level.</p>
<h2 id="examples"><a href="#examples">Examples</a></h2>
<div class='information'><div class='tooltip edition' data-edition="2018"></div></div><div class="example-wrap"><pre class="rust rust-example-rendered edition"><code><span class="kw">use</span> <span class="ident">log::trace</span>;
<span class="kw">let</span> <span class="ident">pos</span> <span class="op">=</span> <span class="ident">Position</span> { <span class="ident">x</span>: <span class="number">3.234</span>, <span class="ident">y</span>: <span class="op">-</span><span class="number">1.223</span> };
<span class="macro">trace!</span>(<span class="string">&quot;Position is: x: {}, y: {}&quot;</span>, <span class="ident">pos</span>.<span class="ident">x</span>, <span class="ident">pos</span>.<span class="ident">y</span>);
<span class="macro">trace!</span>(<span class="ident">target</span>: <span class="string">&quot;app_events&quot;</span>, <span class="string">&quot;x is {} and y is {}&quot;</span>,
<span class="kw">if</span> <span class="ident">pos</span>.<span class="ident">x</span> <span class="op">&gt;</span><span class="op">=</span> <span class="number">0.0</span> { <span class="string">&quot;positive&quot;</span> } <span class="kw">else</span> { <span class="string">&quot;negative&quot;</span> },
<span class="kw">if</span> <span class="ident">pos</span>.<span class="ident">y</span> <span class="op">&gt;</span><span class="op">=</span> <span class="number">0.0</span> { <span class="string">&quot;positive&quot;</span> } <span class="kw">else</span> { <span class="string">&quot;negative&quot;</span> });</code></pre></div>
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