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<h1 class='fqn'><span class='in-band'><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 id='src-1625' class='srclink' href='../src/log/macros.rs.html#133-145' title='goto source code'>[src]</a></span></h1>
<pre class='rust macro'>
<span class='macro'>macro_rules</span><span class='macro'>!</span> <span class='ident'>log_enabled</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'>lvl</span>:<span class='ident'>expr</span>) <span class='op'>=></span> ({
<span class='kw'>let</span> <span class='ident'>lvl</span> <span class='op'>=</span> <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>lvl</span>;
<span class='op'>!</span><span class='macro'>cfg</span><span class='macro'>!</span>(<span class='ident'>log_level</span> <span class='op'>=</span> <span class='string'>"off"</span>) <span class='op'>&&</span>
(<span class='ident'>lvl</span> <span class='op'><=</span> <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>crate</span>::<span class='ident'>LogLevel</span>::<span class='ident'>Error</span> <span class='op'>||</span> <span class='op'>!</span><span class='macro'>cfg</span><span class='macro'>!</span>(<span class='ident'>log_level</span> <span class='op'>=</span> <span class='string'>"error"</span>)) <span class='op'>&&</span>
(<span class='ident'>lvl</span> <span class='op'><=</span> <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>crate</span>::<span class='ident'>LogLevel</span>::<span class='ident'>Warn</span> <span class='op'>||</span> <span class='op'>!</span><span class='macro'>cfg</span><span class='macro'>!</span>(<span class='ident'>log_level</span> <span class='op'>=</span> <span class='string'>"warn"</span>)) <span class='op'>&&</span>
(<span class='ident'>lvl</span> <span class='op'><=</span> <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>crate</span>::<span class='ident'>LogLevel</span>::<span class='ident'>Debug</span> <span class='op'>||</span> <span class='op'>!</span><span class='macro'>cfg</span><span class='macro'>!</span>(<span class='ident'>log_level</span> <span class='op'>=</span> <span class='string'>"debug"</span>)) <span class='op'>&&</span>
(<span class='ident'>lvl</span> <span class='op'><=</span> <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>crate</span>::<span class='ident'>LogLevel</span>::<span class='ident'>Info</span> <span class='op'>||</span> <span class='op'>!</span><span class='macro'>cfg</span><span class='macro'>!</span>(<span class='ident'>log_level</span> <span class='op'>=</span> <span class='string'>"info"</span>)) <span class='op'>&&</span>
<span class='ident'>lvl</span> <span class='op'><=</span> <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>crate</span>::<span class='ident'>max_log_level</span>() <span class='op'>&&</span>
<span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>crate</span>::<span class='ident'>__enabled</span>(<span class='ident'>lvl</span>, <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>target</span>)
});
(<span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>lvl</span>:<span class='ident'>expr</span>) <span class='op'>=></span> (<span class='macro'>log_enabled</span><span class='macro'>!</span>(<span class='ident'>target</span>: <span class='macro'>module_path</span><span class='macro'>!</span>(), <span class='macro-nonterminal'>$</span><span class='macro-nonterminal'>lvl</span>))
}
</pre>
<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>
<h1 id="examples" class='section-header'><a
href="#examples">Examples</a></h1><pre class='rust rust-example-rendered'>
<span class='kw'>use</span> <span class='ident'>log</span>::<span class='ident'>LogLevel</span>::<span class='ident'>Debug</span>;
<span class='kw'>if</span> <span class='macro'>log_enabled</span><span class='macro'>!</span>(<span class='ident'>Debug</span>) {
<span class='macro'>debug</span><span class='macro'>!</span>(<span class='string'>"expensive debug data: {}"</span>, <span class='ident'>expensive_call</span>());
}
</pre>
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