rtic/dev/api/cfg_if/index.html
2024-10-24 05:57:30 +00:00

19 lines
No EOL
4.4 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="A macro for defining `#[cfg]` if-else statements."><title>cfg_if - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-46f98efaafac5295.ttf.woff2,FiraSans-Regular-018c141bf0843ffd.woff2,FiraSans-Medium-8f9a781e4970d388.woff2,SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2,SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2" crossorigin href="../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../static.files/rustdoc-492a78a4a87dcc01.css"><meta name="rustdoc-vars" data-root-path="../" data-static-root-path="../static.files/" data-current-crate="cfg_if" data-themes="" data-resource-suffix="" data-rustdoc-version="1.82.0 (f6e511eec 2024-10-15)" data-channel="1.82.0" data-search-js="search-a99f1315e7cc5121.js" data-settings-js="settings-4313503d2e1961c2.js" ><script src="../static.files/storage-118b08c4c78b968e.js"></script><script defer src="../crates.js"></script><script defer src="../static.files/main-921df33f47b8780c.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-3b12f09e550e0385.css"></noscript><link rel="alternate icon" type="image/png" href="../static.files/favicon-32x32-422f7d1d52889060.png"><link rel="icon" type="image/svg+xml" href="../static.files/favicon-2c020d218678b618.svg"></head><body class="rustdoc mod crate"><!--[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></nav><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../cfg_if/index.html">cfg_if</a><span class="version">1.0.0</span></h2></div><div class="sidebar-elems"><ul class="block"><li><a id="all-types" href="all.html">All Items</a></li></ul><section><ul class="block"><li><a href="#macros">Macros</a></li></ul></section></div></nav><div class="sidebar-resizer"></div><main><div class="width-limiter"><rustdoc-search></rustdoc-search><section id="main-content" class="content"><div class="main-heading"><h1>Crate <a class="mod" href="#">cfg_if</a><button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><span class="out-of-band"><a class="src" href="../src/cfg_if/lib.rs.html#1-176">source</a> · <button id="toggle-all-docs" title="collapse all docs">[<span>&#x2212;</span>]</button></span></div><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>A macro for defining <code>#[cfg]</code> if-else statements.</p>
<p>The macro provided by this crate, <code>cfg_if</code>, is similar to the <code>if/elif</code> C
preprocessor macro by allowing definition of a cascade of <code>#[cfg]</code> cases,
emitting the implementation which matches first.</p>
<p>This allows you to conveniently provide a long list <code>#[cfg]</code>d blocks of code
without having to rewrite each clause multiple times.</p>
<h2 id="example"><a class="doc-anchor" href="#example">§</a>Example</h2>
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="macro">cfg_if::cfg_if!</span> {
<span class="kw">if </span><span class="attr">#[cfg(unix)] </span>{
<span class="kw">fn </span>foo() { <span class="comment">/* unix specific functionality */ </span>}
} <span class="kw">else if </span><span class="attr">#[cfg(target_pointer_width = <span class="string">"32"</span>)] </span>{
<span class="kw">fn </span>foo() { <span class="comment">/* non-unix, 32-bit functionality */ </span>}
} <span class="kw">else </span>{
<span class="kw">fn </span>foo() { <span class="comment">/* fallback implementation */ </span>}
}
}
</code></pre></div>
</div></details><h2 id="macros" class="section-header">Macros<a href="#macros" class="anchor">§</a></h2><ul class="item-table"><li><div class="item-name"><a class="macro" href="macro.cfg_if.html" title="macro cfg_if::cfg_if">cfg_if</a></div><div class="desc docblock-short">The main macro provided by this crate. See crate documentation for more
information.</div></li></ul></section></div></main></body></html>