131 lines
5.6 KiB
HTML
131 lines
5.6 KiB
HTML
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<p class='location'><a href='index.html'>log</a></p><script>window.sidebarCurrent = {name: 'log_enabled', ty: 'macro', relpath: ''};</script><script defer src="sidebar-items.js"></script>
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<h1 class='fqn'><span class='in-band'>Macro <a href='index.html'>log</a>::<wbr><a class="macro" href=''>log_enabled</a></span><span class='out-of-band'><span id='render-detail'>
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</span><a class='srclink' href='../src/log/macros.rs.html#236-243' title='goto source code'>[src]</a></span></h1>
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<pre class="rust macro">
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<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">log_enabled</span> {
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(<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">lvl</span>:<span class="ident">expr</span>) <span class="op">=></span> { ... };
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(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">lvl</span>:<span class="ident">expr</span>) <span class="op">=></span> { ... };
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}</pre>
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<div class='docblock'><p>Determines if a message logged at the specified level in that module will
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be logged.</p>
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<p>This can be used to avoid expensive computation of log message arguments if
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the message would be ignored anyway.</p>
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<h1 id='examples' class='section-header'><a href='#examples'>Examples</a></h1>
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<pre class="rust rust-example-rendered">
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<span class="kw">use</span> <span class="ident">log</span>::<span class="ident">LogLevel</span>::<span class="ident">Debug</span>;
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<span class="kw">if</span> <span class="macro">log_enabled</span><span class="macro">!</span>(<span class="ident">Debug</span>) {
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<span class="kw">let</span> <span class="ident">data</span> <span class="op">=</span> <span class="ident">expensive_call</span>();
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<span class="macro">debug</span><span class="macro">!</span>(<span class="string">"expensive debug data: {} {}"</span>, <span class="ident">data</span>.<span class="ident">x</span>, <span class="ident">data</span>.<span class="ident">y</span>);
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}</pre>
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