You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
Trac3r-rust/doc/bitflags/index.html

212 lines
22 KiB

This file contains ambiguous Unicode characters!

This file contains ambiguous Unicode characters that may be confused with others in your current locale. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to highlight these characters.

<!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="API documentation for the Rust `bitflags` crate."><meta name="keywords" content="rust, rustlang, rust-lang, bitflags"><title>bitflags - Rust</title><link rel="stylesheet" type="text/css" href="../normalize.css"><link rel="stylesheet" type="text/css" href="../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../dark.css"><link rel="stylesheet" type="text/css" href="../light.css" id="themeStyle"><script src="../storage.js"></script><noscript><link rel="stylesheet" href="../noscript.css"></noscript><link rel="shortcut icon" href="../favicon.ico"><style type="text/css">#crate-search{background-image:url("../down-arrow.svg");}</style></head><body class="rustdoc mod"><!--[if lte IE 8]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><div class="sidebar-menu">&#9776;</div><a href='../bitflags/index.html'><div class='logo-container'><img src='../rust-logo.png' alt='logo'></div></a><p class='location'>Crate bitflags</p><div class="sidebar-elems"><a id='all-types' href='all.html'><p>See all bitflags's items</p></a><div class="block items"><ul><li><a href="#macros">Macros</a></li></ul></div><p class='location'></p><script>window.sidebarCurrent = {name: 'bitflags', ty: 'mod', relpath: '../'};</script></div></nav><div class="theme-picker"><button id="theme-picker" aria-label="Pick another theme!"><img src="../brush.svg" width="18" alt="Pick another theme!"></button><div id="theme-choices"></div></div><script src="../theme.js"></script><nav class="sub"><form class="search-form js-only"><div class="search-container"><div><select id="crate-search"><option value="All crates">All crates</option></select><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press S to search, ? for more options…" type="search"></div><a id="settings-menu" href="../settings.html"><img src="../wheel.svg" width="18" alt="Change settings"></a></div></form></nav><section id="main" class="content"><h1 class='fqn'><span class='out-of-band'><span id='render-detail'><a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class='inner'>&#x2212;</span>]</a></span><a class='srclink' href='../src/bitflags/lib.rs.html#11-1353' title='goto source code'>[src]</a></span><span class='in-band'>Crate <a class="mod" href=''>bitflags</a></span></h1><div class='docblock'><p>A typesafe bitmask flag generator useful for sets of C-style bitmask flags.
It can be used for creating typesafe wrappers around C APIs.</p>
<p>The <code>bitflags!</code> macro generates a <code>struct</code> that manages a set of flags. The
flags should only be defined for integer types, otherwise unexpected type
errors may occur at compile time.</p>
<h1 id="example" class="section-header"><a href="#example">Example</a></h1>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="attribute">#[<span class="ident">macro_use</span>]</span>
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">bitflags</span>;
<span class="macro">bitflags</span><span class="macro">!</span> {
<span class="kw">struct</span> <span class="ident">Flags</span>: <span class="ident">u32</span> {
<span class="kw">const</span> <span class="ident">A</span> <span class="op">=</span> <span class="number">0b00000001</span>;
<span class="kw">const</span> <span class="ident">B</span> <span class="op">=</span> <span class="number">0b00000010</span>;
<span class="kw">const</span> <span class="ident">C</span> <span class="op">=</span> <span class="number">0b00000100</span>;
<span class="kw">const</span> <span class="ident">ABC</span> <span class="op">=</span> <span class="self">Self</span>::<span class="ident">A</span>.<span class="ident">bits</span> <span class="op">|</span> <span class="self">Self</span>::<span class="ident">B</span>.<span class="ident">bits</span> <span class="op">|</span> <span class="self">Self</span>::<span class="ident">C</span>.<span class="ident">bits</span>;
}
}
<span class="kw">fn</span> <span class="ident">main</span>() {
<span class="kw">let</span> <span class="ident">e1</span> <span class="op">=</span> <span class="ident">Flags</span>::<span class="ident">A</span> <span class="op">|</span> <span class="ident">Flags</span>::<span class="ident">C</span>;
<span class="kw">let</span> <span class="ident">e2</span> <span class="op">=</span> <span class="ident">Flags</span>::<span class="ident">B</span> <span class="op">|</span> <span class="ident">Flags</span>::<span class="ident">C</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>((<span class="ident">e1</span> <span class="op">|</span> <span class="ident">e2</span>), <span class="ident">Flags</span>::<span class="ident">ABC</span>); <span class="comment">// union</span>
<span class="macro">assert_eq</span><span class="macro">!</span>((<span class="ident">e1</span> <span class="op">&amp;</span> <span class="ident">e2</span>), <span class="ident">Flags</span>::<span class="ident">C</span>); <span class="comment">// intersection</span>
<span class="macro">assert_eq</span><span class="macro">!</span>((<span class="ident">e1</span> <span class="op">-</span> <span class="ident">e2</span>), <span class="ident">Flags</span>::<span class="ident">A</span>); <span class="comment">// set difference</span>
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="op">!</span><span class="ident">e2</span>, <span class="ident">Flags</span>::<span class="ident">A</span>); <span class="comment">// set complement</span>
}</pre></div>
<p>See <a href="./example_generated/struct.Flags.html"><code>example_generated::Flags</code></a> for documentation of code
generated by the above <code>bitflags!</code> expansion.</p>
<p>The generated <code>struct</code>s can also be extended with type and trait
implementations:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="attribute">#[<span class="ident">macro_use</span>]</span>
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">bitflags</span>;
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">fmt</span>;
<span class="macro">bitflags</span><span class="macro">!</span> {
<span class="kw">struct</span> <span class="ident">Flags</span>: <span class="ident">u32</span> {
<span class="kw">const</span> <span class="ident">A</span> <span class="op">=</span> <span class="number">0b00000001</span>;
<span class="kw">const</span> <span class="ident">B</span> <span class="op">=</span> <span class="number">0b00000010</span>;
}
}
<span class="kw">impl</span> <span class="ident">Flags</span> {
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">clear</span>(<span class="kw-2">&amp;</span><span class="kw-2">mut</span> <span class="self">self</span>) {
<span class="self">self</span>.<span class="ident">bits</span> <span class="op">=</span> <span class="number">0</span>; <span class="comment">// The `bits` field can be accessed from within the</span>
<span class="comment">// same module where the `bitflags!` macro was invoked.</span>
}
}
<span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Display</span> <span class="kw">for</span> <span class="ident">Flags</span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&amp;</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-</span><span class="op">&gt;</span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
<span class="macro">write</span><span class="macro">!</span>(<span class="ident">f</span>, <span class="string">&quot;hi!&quot;</span>)
}
}
<span class="kw">fn</span> <span class="ident">main</span>() {
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">flags</span> <span class="op">=</span> <span class="ident">Flags</span>::<span class="ident">A</span> <span class="op">|</span> <span class="ident">Flags</span>::<span class="ident">B</span>;
<span class="ident">flags</span>.<span class="ident">clear</span>();
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">flags</span>.<span class="ident">is_empty</span>());
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="macro">format</span><span class="macro">!</span>(<span class="string">&quot;{}&quot;</span>, <span class="ident">flags</span>), <span class="string">&quot;hi!&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="macro">format</span><span class="macro">!</span>(<span class="string">&quot;{:?}&quot;</span>, <span class="ident">Flags</span>::<span class="ident">A</span> <span class="op">|</span> <span class="ident">Flags</span>::<span class="ident">B</span>), <span class="string">&quot;A | B&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="macro">format</span><span class="macro">!</span>(<span class="string">&quot;{:?}&quot;</span>, <span class="ident">Flags</span>::<span class="ident">B</span>), <span class="string">&quot;B&quot;</span>);
}</pre></div>
<h1 id="visibility" class="section-header"><a href="#visibility">Visibility</a></h1>
<p>The generated struct and its associated flag constants are not exported
out of the current module by default. A definition can be exported out of
the current module by adding <code>pub</code> before <code>flags</code>:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="attribute">#[<span class="ident">macro_use</span>]</span>
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">bitflags</span>;
<span class="kw">mod</span> <span class="ident">example</span> {
<span class="macro">bitflags</span><span class="macro">!</span> {
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">Flags1</span>: <span class="ident">u32</span> {
<span class="kw">const</span> <span class="ident">A</span> <span class="op">=</span> <span class="number">0b00000001</span>;
}
}
<span class="macro">bitflags</span><span class="macro">!</span> {
<span class="kw">struct</span> <span class="ident">Flags2</span>: <span class="ident">u32</span> {
<span class="kw">const</span> <span class="ident">B</span> <span class="op">=</span> <span class="number">0b00000010</span>;
}
}
}
<span class="kw">fn</span> <span class="ident">main</span>() {
<span class="kw">let</span> <span class="ident">flag1</span> <span class="op">=</span> <span class="ident">example</span>::<span class="ident">Flags1</span>::<span class="ident">A</span>;
<span class="kw">let</span> <span class="ident">flag2</span> <span class="op">=</span> <span class="ident">example</span>::<span class="ident">Flags2</span>::<span class="ident">B</span>; <span class="comment">// error: const `B` is private</span>
}</pre></div>
<h1 id="attributes" class="section-header"><a href="#attributes">Attributes</a></h1>
<p>Attributes can be attached to the generated <code>struct</code> by placing them
before the <code>flags</code> keyword.</p>
<h1 id="trait-implementations" class="section-header"><a href="#trait-implementations">Trait implementations</a></h1>
<p>The <code>Copy</code>, <code>Clone</code>, <code>PartialEq</code>, <code>Eq</code>, <code>PartialOrd</code>, <code>Ord</code> and <code>Hash</code>
traits automatically derived for the <code>struct</code> using the <code>derive</code> attribute.
Additional traits can be derived by providing an explicit <code>derive</code>
attribute on <code>flags</code>.</p>
<p>The <code>Extend</code> and <code>FromIterator</code> traits are implemented for the <code>struct</code>,
too: <code>Extend</code> adds the union of the instances of the <code>struct</code> iterated over,
while <code>FromIterator</code> calculates the union.</p>
<p>The <code>Binary</code>, <code>Debug</code>, <code>LowerExp</code>, <code>Octal</code> and <code>UpperExp</code> trait is also
implemented by displaying the bits value of the internal struct.</p>
<h2 id="operators" class="section-header"><a href="#operators">Operators</a></h2>
<p>The following operator traits are implemented for the generated <code>struct</code>:</p>
<ul>
<li><code>BitOr</code> and <code>BitOrAssign</code>: union</li>
<li><code>BitAnd</code> and <code>BitAndAssign</code>: intersection</li>
<li><code>BitXor</code> and <code>BitXorAssign</code>: toggle</li>
<li><code>Sub</code> and <code>SubAssign</code>: set difference</li>
<li><code>Not</code>: set complement</li>
</ul>
<h1 id="methods-1" class="section-header"><a href="#methods-1">Methods</a></h1>
<p>The following methods are defined for the generated <code>struct</code>:</p>
<ul>
<li><code>empty</code>: an empty set of flags</li>
<li><code>all</code>: the set of all flags</li>
<li><code>bits</code>: the raw value of the flags currently stored</li>
<li><code>from_bits</code>: convert from underlying bit representation, unless that
representation contains bits that do not correspond to a flag</li>
<li><code>from_bits_truncate</code>: convert from underlying bit representation, dropping
any bits that do not correspond to flags</li>
<li><code>is_empty</code>: <code>true</code> if no flags are currently stored</li>
<li><code>is_all</code>: <code>true</code> if all flags are currently set</li>
<li><code>intersects</code>: <code>true</code> if there are flags common to both <code>self</code> and <code>other</code></li>
<li><code>contains</code>: <code>true</code> all of the flags in <code>other</code> are contained within <code>self</code></li>
<li><code>insert</code>: inserts the specified flags in-place</li>
<li><code>remove</code>: removes the specified flags in-place</li>
<li><code>toggle</code>: the specified flags will be inserted if not present, and removed
if they are.</li>
<li><code>set</code>: inserts or removes the specified flags depending on the passed value</li>
</ul>
<h2 id="default" class="section-header"><a href="#default">Default</a></h2>
<p>The <code>Default</code> trait is not automatically implemented for the generated struct.</p>
<p>If your default value is equal to <code>0</code> (which is the same value as calling <code>empty()</code>
on the generated struct), you can simply derive <code>Default</code>:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="attribute">#[<span class="ident">macro_use</span>]</span>
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">bitflags</span>;
<span class="macro">bitflags</span><span class="macro">!</span> {
<span class="comment">// Results in default value with bits: 0</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Default</span>)]</span>
<span class="kw">struct</span> <span class="ident">Flags</span>: <span class="ident">u32</span> {
<span class="kw">const</span> <span class="ident">A</span> <span class="op">=</span> <span class="number">0b00000001</span>;
<span class="kw">const</span> <span class="ident">B</span> <span class="op">=</span> <span class="number">0b00000010</span>;
<span class="kw">const</span> <span class="ident">C</span> <span class="op">=</span> <span class="number">0b00000100</span>;
}
}
<span class="kw">fn</span> <span class="ident">main</span>() {
<span class="kw">let</span> <span class="ident">derived_default</span>: <span class="ident">Flags</span> <span class="op">=</span> <span class="ident">Default</span>::<span class="ident">default</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">derived_default</span>.<span class="ident">bits</span>(), <span class="number">0</span>);
}</pre></div>
<p>If your default value is not equal to <code>0</code> you need to implement <code>Default</code> yourself:</p>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="attribute">#[<span class="ident">macro_use</span>]</span>
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">bitflags</span>;
<span class="macro">bitflags</span><span class="macro">!</span> {
<span class="kw">struct</span> <span class="ident">Flags</span>: <span class="ident">u32</span> {
<span class="kw">const</span> <span class="ident">A</span> <span class="op">=</span> <span class="number">0b00000001</span>;
<span class="kw">const</span> <span class="ident">B</span> <span class="op">=</span> <span class="number">0b00000010</span>;
<span class="kw">const</span> <span class="ident">C</span> <span class="op">=</span> <span class="number">0b00000100</span>;
}
}
<span class="comment">// explicit `Default` implementation</span>
<span class="kw">impl</span> <span class="ident">Default</span> <span class="kw">for</span> <span class="ident">Flags</span> {
<span class="kw">fn</span> <span class="ident">default</span>() <span class="op">-</span><span class="op">&gt;</span> <span class="ident">Flags</span> {
<span class="ident">Flags</span>::<span class="ident">A</span> <span class="op">|</span> <span class="ident">Flags</span>::<span class="ident">C</span>
}
}
<span class="kw">fn</span> <span class="ident">main</span>() {
<span class="kw">let</span> <span class="ident">implemented_default</span>: <span class="ident">Flags</span> <span class="op">=</span> <span class="ident">Default</span>::<span class="ident">default</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">implemented_default</span>, (<span class="ident">Flags</span>::<span class="ident">A</span> <span class="op">|</span> <span class="ident">Flags</span>::<span class="ident">C</span>));
}</pre></div>
<h1 id="zero-flags" class="section-header"><a href="#zero-flags">Zero Flags</a></h1>
<p>Flags with a value equal to zero will have some strange behavior that one should be aware of.</p>
<div class="example-wrap"><pre class="rust rust-example-rendered">
<span class="attribute">#[<span class="ident">macro_use</span>]</span>
<span class="kw">extern</span> <span class="kw">crate</span> <span class="ident">bitflags</span>;
<span class="macro">bitflags</span><span class="macro">!</span> {
<span class="kw">struct</span> <span class="ident">Flags</span>: <span class="ident">u32</span> {
<span class="kw">const</span> <span class="ident">NONE</span> <span class="op">=</span> <span class="number">0b00000000</span>;
<span class="kw">const</span> <span class="ident">SOME</span> <span class="op">=</span> <span class="number">0b00000001</span>;
}
}
<span class="kw">fn</span> <span class="ident">main</span>() {
<span class="kw">let</span> <span class="ident">empty</span> <span class="op">=</span> <span class="ident">Flags</span>::<span class="ident">empty</span>();
<span class="kw">let</span> <span class="ident">none</span> <span class="op">=</span> <span class="ident">Flags</span>::<span class="ident">NONE</span>;
<span class="kw">let</span> <span class="ident">some</span> <span class="op">=</span> <span class="ident">Flags</span>::<span class="ident">SOME</span>;
<span class="comment">// Zero flags are treated as always present</span>
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">empty</span>.<span class="ident">contains</span>(<span class="ident">Flags</span>::<span class="ident">NONE</span>));
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">none</span>.<span class="ident">contains</span>(<span class="ident">Flags</span>::<span class="ident">NONE</span>));
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">some</span>.<span class="ident">contains</span>(<span class="ident">Flags</span>::<span class="ident">NONE</span>));
<span class="comment">// Zero flags will be ignored when testing for emptiness</span>
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">none</span>.<span class="ident">is_empty</span>());
}</pre></div>
</div><h2 id='macros' class='section-header'><a href="#macros">Macros</a></h2>
<table><tr class='module-item'><td><a class="macro" href="macro.bitflags.html" title='bitflags::bitflags macro'>bitflags</a></td><td class='docblock-short'><p>The macro used to generate the flag structure.</p>
</td></tr></table></section><section id="search" class="content hidden"></section><section class="footer"></section><aside id="help" class="hidden"><div><h1 class="hidden">Help</h1><div class="shortcuts"><h2>Keyboard Shortcuts</h2><dl><dt><kbd>?</kbd></dt><dd>Show this help dialog</dd><dt><kbd>S</kbd></dt><dd>Focus the search field</dd><dt><kbd></kbd></dt><dd>Move up in search results</dd><dt><kbd></kbd></dt><dd>Move down in search results</dd><dt><kbd></kbd></dt><dd>Switch tab</dd><dt><kbd>&#9166;</kbd></dt><dd>Go to active search result</dd><dt><kbd>+</kbd></dt><dd>Expand all sections</dd><dt><kbd>-</kbd></dt><dd>Collapse all sections</dd></dl></div><div class="infos"><h2>Search Tricks</h2><p>Prefix searches with a type followed by a colon (e.g., <code>fn:</code>) to restrict the search to a given type.</p><p>Accepted types are: <code>fn</code>, <code>mod</code>, <code>struct</code>, <code>enum</code>, <code>trait</code>, <code>type</code>, <code>macro</code>, and <code>const</code>.</p><p>Search functions by type signature (e.g., <code>vec -> usize</code> or <code>* -> vec</code>)</p><p>Search multiple things at once by splitting your query with comma (e.g., <code>str,u8</code> or <code>String,struct:Vec,test</code>)</p></div></div></aside><script>window.rootPath = "../";window.currentCrate = "bitflags";</script><script src="../aliases.js"></script><script src="../main.js"></script><script defer src="../search-index.js"></script></body></html>