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<h1 class='fqn'><span class='in-band'>Macro <a href='index.html'>std</a>::<wbr><a class="macro" href=''>thread_local</a></span><span class='out-of-band'><span class='since' title='Stable since Rust version 1.0.0'>1.0.0</span><span id='render-detail'>
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</span><a class='srclink' href='../src/std/thread/local.rs.html#138-165' 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">thread_local</span> {
() <span class="op">=></span> { ... };
($(<span class="attribute">#[<span class="macro-nonterminal">$</span><span class="macro-nonterminal">attr</span>:<span class="ident">meta</span>]</span>)<span class="op">*</span> <span class="kw">static</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">name</span>:<span class="ident">ident</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">t</span>:<span class="ident">ty</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">init</span>:<span class="ident">expr</span>; $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=></span> { ... };
($(<span class="attribute">#[<span class="macro-nonterminal">$</span><span class="macro-nonterminal">attr</span>:<span class="ident">meta</span>]</span>)<span class="op">*</span> <span class="kw">static</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">name</span>:<span class="ident">ident</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">t</span>:<span class="ident">ty</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">init</span>:<span class="ident">expr</span>) <span class="op">=></span> { ... };
($(<span class="attribute">#[<span class="macro-nonterminal">$</span><span class="macro-nonterminal">attr</span>:<span class="ident">meta</span>]</span>)<span class="op">*</span> <span class="kw">pub</span> <span class="kw">static</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">name</span>:<span class="ident">ident</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">t</span>:<span class="ident">ty</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">init</span>:<span class="ident">expr</span>; $(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">rest</span>:<span class="ident">tt</span>)<span class="kw-2">*</span>) <span class="op">=></span> { ... };
($(<span class="attribute">#[<span class="macro-nonterminal">$</span><span class="macro-nonterminal">attr</span>:<span class="ident">meta</span>]</span>)<span class="op">*</span> <span class="kw">pub</span> <span class="kw">static</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">name</span>:<span class="ident">ident</span>: <span class="macro-nonterminal">$</span><span class="macro-nonterminal">t</span>:<span class="ident">ty</span> <span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">init</span>:<span class="ident">expr</span>) <span class="op">=></span> { ... };
}</pre>
<div class='docblock'><p>Declare a new thread local storage key of type <a href="../std/thread/struct.LocalKey.html"><code>std::thread::LocalKey</code></a>.</p>
<h1 id='syntax' class='section-header'><a href='#syntax'>Syntax</a></h1>
<p>The macro wraps any number of static declarations and makes them thread local.
Each static may be public or private, and attributes are allowed. Example:</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">cell</span>::<span class="ident">RefCell</span>;
<span class="macro">thread_local</span><span class="macro">!</span> {
<span class="kw">pub</span> <span class="kw">static</span> <span class="ident">FOO</span>: <span class="ident">RefCell</span><span class="op"><</span><span class="ident">u32</span><span class="op">></span> <span class="op">=</span> <span class="ident">RefCell</span>::<span class="ident">new</span>(<span class="number">1</span>);
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">unused</span>)]</span>
<span class="kw">static</span> <span class="ident">BAR</span>: <span class="ident">RefCell</span><span class="op"><</span><span class="ident">f32</span><span class="op">></span> <span class="op">=</span> <span class="ident">RefCell</span>::<span class="ident">new</span>(<span class="number">1.0</span>);
}<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=use%20std%3A%3Acell%3A%3ARefCell%3B%0Athread_local!%20%7B%0A%20%20%20%20pub%20static%20FOO%3A%20RefCell%3Cu32%3E%20%3D%20RefCell%3A%3Anew(1)%3B%0A%0A%20%20%20%20%23%5Ballow(unused)%5D%0A%20%20%20%20static%20BAR%3A%20RefCell%3Cf32%3E%20%3D%20RefCell%3A%3Anew(1.0)%3B%0A%7D%0Afn%20main()%20%7B%7D%0A">Run</a></pre>
<p>See <a href="../std/thread/struct.LocalKey.html">LocalKey documentation</a> for more
information.</p>
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