39 lines
6.1 KiB
HTML
39 lines
6.1 KiB
HTML
<!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="You can use `mut_array_refs` to generate a series of mutable array references to an input mutable array reference. The idea is if you want to break an array into a series of contiguous and non-overlapping mutable array references. Like `array_refs!`, `mut_array_refs!` is a bit funny in that it insists on slicing up the entire array. This is intentional, as I find it handy to make me ensure that my sub-arrays add up to the entire array. This macro will never panic, since the sizes are all checked at compile time."><title>mut_array_refs in arrayref - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.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-9960930a.css"><link rel="stylesheet" href="../static.files/rustdoc-42caa33d.css"><meta name="rustdoc-vars" data-root-path="../" data-static-root-path="../static.files/" data-current-crate="arrayref" data-themes="" data-resource-suffix="" data-rustdoc-version="1.84.0 (9fc6b4312 2025-01-07)" data-channel="1.84.0" data-search-js="search-92e6798f.js" data-settings-js="settings-0f613d39.js" ><script src="../static.files/storage-59e33391.js"></script><script defer src="sidebar-items.js"></script><script defer src="../static.files/main-5f194d8c.js"></script><noscript><link rel="stylesheet" href="../static.files/noscript-893ab5e7.css"></noscript><link rel="alternate icon" type="image/png" href="../static.files/favicon-32x32-6580c154.png"><link rel="icon" type="image/svg+xml" href="../static.files/favicon-044be391.svg"></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></nav><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../arrayref/index.html">arrayref</a><span class="version">0.3.9</span></h2></div><div class="sidebar-elems"><div id="rustdoc-modnav"></div></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"><span class="rustdoc-breadcrumbs"><a href="index.html">arrayref</a></span><h1>Macro <span class="macro">mut_array_refs</span><button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"><a class="src" href="../src/arrayref/lib.rs.html#202-256">Source</a> </span></div><pre class="rust item-decl"><code>macro_rules! mut_array_refs {
|
|
( $arr:expr, $( $pre:expr ),* ; .. ; $( $post:expr ),* ) => { ... };
|
|
( $arr:expr, $( $len:expr ),* ) => { ... };
|
|
}</code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>You can use <code>mut_array_refs</code> to generate a series of mutable array
|
|
references to an input mutable array reference. The idea is if
|
|
you want to break an array into a series of contiguous and
|
|
non-overlapping mutable array references. Like <code>array_refs!</code>,
|
|
<code>mut_array_refs!</code> is a bit funny in that it insists on slicing up
|
|
the <em>entire</em> array. This is intentional, as I find it handy to
|
|
make me ensure that my sub-arrays add up to the entire array.
|
|
This macro will <em>never</em> panic, since the sizes are all checked at
|
|
compile time.</p>
|
|
<p>Note that unlike <code>array_mut_ref!</code>, <code>mut_array_refs</code> <em>requires</em>
|
|
that the first argument be a mutable array reference. The
|
|
following arguments are the lengths of each subarray you wish a
|
|
reference to. The total of these arguments <em>must</em> equal the size
|
|
of the array itself. Also note that this macro allows you to take
|
|
out multiple mutable references to a single object, which is both
|
|
weird and powerful.</p>
|
|
|
|
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="attr">#[macro_use]
|
|
</span><span class="kw">extern crate </span>arrayref;
|
|
|
|
<span class="kw">fn </span>write_u16(bytes: <span class="kw-2">&mut </span>[u8; <span class="number">2</span>], num: u16) {
|
|
bytes[<span class="number">0</span>] = num <span class="kw">as </span>u8;
|
|
bytes[<span class="number">1</span>] = (num >> <span class="number">8</span>) <span class="kw">as </span>u8;
|
|
}
|
|
<span class="kw">fn </span>write_u32(bytes: <span class="kw-2">&mut </span>[u8; <span class="number">4</span>], num: u32) {
|
|
bytes[<span class="number">0</span>] = num <span class="kw">as </span>u8;
|
|
bytes[<span class="number">1</span>] = (num >> <span class="number">8</span>) <span class="kw">as </span>u8; <span class="comment">// this is buggy to save space...
|
|
</span>}
|
|
<span class="comment">// ...
|
|
</span><span class="kw">let </span><span class="kw-2">mut </span>data = [<span class="number">0</span>,<span class="number">1</span>,<span class="number">2</span>,<span class="number">3</span>,<span class="number">4</span>,<span class="number">0</span>,<span class="number">6</span>,<span class="number">7</span>];
|
|
<span class="kw">let </span>(a,b,c) = <span class="macro">mut_array_refs!</span>[<span class="kw-2">&mut </span>data,<span class="number">2</span>,<span class="number">2</span>,<span class="number">4</span>];
|
|
<span class="comment">// let's write out some nice prime numbers!
|
|
</span>write_u16(a, <span class="number">37</span>);
|
|
write_u16(b, <span class="number">73</span>);
|
|
write_u32(c, <span class="number">137</span>); <span class="comment">// approximate inverse of the fine structure constant!</span></code></pre></div>
|
|
</div></details></section></div></main></body></html> |