edlang/log/macro.log_enabled.html
2024-04-09 10:18:33 +00:00

21 lines
5.2 KiB
HTML
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!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="Determines if a message logged at the specified level in that module will be logged."><title>log_enabled in log - Rust</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/SourceSerif4-Regular-46f98efaafac5295.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/FiraSans-Regular-018c141bf0843ffd.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/FiraSans-Medium-8f9a781e4970d388.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2"><link rel="stylesheet" href="../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../static.files/rustdoc-5bc39a1768837dd0.css"><meta name="rustdoc-vars" data-root-path="../" data-static-root-path="../static.files/" data-current-crate="log" data-themes="" data-resource-suffix="" data-rustdoc-version="1.77.1 (7cf61ebde 2024-03-27)" data-channel="1.77.1" data-search-js="search-dd67cee4cfa65049.js" data-settings-js="settings-4313503d2e1961c2.js" ><script src="../static.files/storage-4c98445ec4002617.js"></script><script defer src="sidebar-items.js"></script><script defer src="../static.files/main-48f368f3872407c8.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-04d5337699b92874.css"></noscript><link rel="icon" href="https://www.rust-lang.org/favicon.ico"></head><body class="rustdoc macro"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="mobile-topbar"><button class="sidebar-menu-toggle" title="show sidebar"></button><a class="logo-container" href="../log/index.html"><img src="https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png" alt=""></a></nav><nav class="sidebar"><div class="sidebar-crate"><a class="logo-container" href="../log/index.html"><img src="https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png" alt="logo"></a><h2><a href="../log/index.html">log</a><span class="version">0.4.21</span></h2></div><div class="sidebar-elems"></div></nav><div class="sidebar-resizer"></div>
<main><div class="width-limiter"><nav class="sub"><form class="search-form"><span></span><div id="sidebar-button" tabindex="-1"><a href="../log/all.html" title="show sidebar"></a></div><input class="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"><div id="help-button" tabindex="-1"><a href="../help.html" title="help">?</a></div><div id="settings-menu" tabindex="-1"><a href="../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../static.files/wheel-7b819b6101059cd0.svg"></a></div></form></nav><section id="main-content" class="content"><div class="main-heading"><h1>Macro <a href="index.html">log</a>::<wbr><a class="macro" href="#">log_enabled</a><button id="copy-path" title="Copy item path to clipboard"><img src="../static.files/clipboard-7571035ce49a181d.svg" width="19" height="18" alt="Copy item path"></button></h1><span class="out-of-band"><a class="src" href="../src/log/macros.rs.html#217-227">source</a> · <button id="toggle-all-docs" title="collapse all docs">[<span>&#x2212;</span>]</button></span></div><pre class="rust item-decl"><span class="macro">macro_rules! </span>log_enabled {
(target: <span class="macro-nonterminal">$target</span>:expr, <span class="macro-nonterminal">$lvl</span>:expr) =&gt; { ... };
(<span class="macro-nonterminal">$lvl</span>:expr) =&gt; { ... };
}</pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Determines if a message logged at the specified level in that module will
be logged.</p>
<p>This can be used to avoid expensive computation of log message arguments if
the message would be ignored anyway.</p>
<h2 id="examples"><a class="doc-anchor" href="#examples">§</a>Examples</h2>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>log::Level::Debug;
<span class="kw">use </span>log::{debug, log_enabled};
<span class="kw">if </span><span class="macro">log_enabled!</span>(Debug) {
<span class="kw">let </span>data = expensive_call();
<span class="macro">debug!</span>(<span class="string">"expensive debug data: {} {}"</span>, data.x, data.y);
}
<span class="kw">if </span><span class="macro">log_enabled!</span>(target: <span class="string">"Global"</span>, Debug) {
<span class="kw">let </span>data = expensive_call();
<span class="macro">debug!</span>(target: <span class="string">"Global"</span>, <span class="string">"expensive debug data: {} {}"</span>, data.x, data.y);
}</code></pre></div>
</div></details></section></div></main></body></html>