<!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 `GlobalAlloc` trait in crate `core`."><meta name="keywords" content="rust, rustlang, rust-lang, GlobalAlloc"><title>core::alloc::GlobalAlloc - 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><link rel="shortcut icon" href="https://doc.rust-lang.org/favicon.ico"></head><body class="rustdoc trait"><!--[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">☰</div><a href='../../core/index.html'><img src='https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png' alt='logo' width='100'></a><p class='location'>Trait GlobalAlloc</p><div class="sidebar-elems"><div class="block items"><a class="sidebar-title" href="#required-methods">Required Methods</a><div class="sidebar-links"><a href="#tymethod.alloc">alloc</a><a href="#tymethod.dealloc">dealloc</a></div><a class="sidebar-title" href="#provided-methods">Provided Methods</a><div class="sidebar-links"><a href="#method.alloc_zeroed">alloc_zeroed</a><a href="#method.realloc">realloc</a></div><a class="sidebar-title" href="#implementors">Implementors</a></div><p class='location'><a href='../index.html'>core</a>::<wbr><a href='index.html'>alloc</a></p><script>window.sidebarCurrent = {name: 'GlobalAlloc', ty: 'trait', relpath: ''};</script><script defer src="sidebar-items.js"></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"><input class="search-input" name="search" autocomplete="off" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><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='in-band'>Trait <a href='../index.html'>core</a>::<wbr><a href='index.html'>alloc</a>::<wbr><a class="trait" href=''>GlobalAlloc</a></span><span class='out-of-band'><span class='since' title='Stable since Rust version '></span><span id='render-detail'><a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs">[<span class='inner'>−</span>]</a></span><a class='srclink' href='../../src/core/alloc.rs.html#397-454' title='goto source code'>[src]</a></span></h1><div class="docblock type-decl"><pre class='rust trait'>pub unsafe trait GlobalAlloc {
unsafe fn <a href='#tymethod.alloc' class='fnname'>alloc</a>(&self, layout: <a class="struct" href="../../core/alloc/struct.Layout.html" title="struct core::alloc::Layout">Layout</a>) -> *mut <a class="foreigntype" href="../../core/alloc/foreigntype.Opaque.html" title="foreigntype core::alloc::Opaque">Opaque</a>;
<div class='item-spacer'></div> unsafe fn <a href='#tymethod.dealloc' class='fnname'>dealloc</a>(&self, ptr: *mut <a class="foreigntype" href="../../core/alloc/foreigntype.Opaque.html" title="foreigntype core::alloc::Opaque">Opaque</a>, layout: <a class="struct" href="../../core/alloc/struct.Layout.html" title="struct core::alloc::Layout">Layout</a>);
unsafe fn <a href='#method.alloc_zeroed' class='fnname'>alloc_zeroed</a>(&self, layout: <a class="struct" href="../../core/alloc/struct.Layout.html" title="struct core::alloc::Layout">Layout</a>) -> *mut <a class="foreigntype" href="../../core/alloc/foreigntype.Opaque.html" title="foreigntype core::alloc::Opaque">Opaque</a> { ... }
<div class='item-spacer'></div> unsafe fn <a href='#method.realloc' class='fnname'>realloc</a>(<br> &self, <br> ptr: *mut <a class="foreigntype" href="../../core/alloc/foreigntype.Opaque.html" title="foreigntype core::alloc::Opaque">Opaque</a>, <br> layout: <a class="struct" href="../../core/alloc/struct.Layout.html" title="struct core::alloc::Layout">Layout</a>, <br> new_size: usize<br> ) -> *mut <a class="foreigntype" href="../../core/alloc/foreigntype.Opaque.html" title="foreigntype core::alloc::Opaque">Opaque</a> { ... }
}</pre></div><div class='stability'><div class='stab unstable'><details><summary><span class=microscope>🔬</span> This is a nightly-only experimental API. (<code>allocator_api </code><a href="https://github.com/rust-lang/rust/issues/32838">#32838</a>)</summary><p>the precise API and guarantees it provides may be tweaked slightly, especially to possibly take into account the types being stored to make room for a future tracing garbage collector</p>
</details></div></div><div class='docblock'><p>A memory allocator that can be registered to be the one backing <code>std::alloc::Global</code>
though the <code>#[global_allocator]</code> attributes.</p>
</div>
<h2 id='required-methods' class='small-section-header'>
Required Methods<a href='#required-methods' class='anchor'></a>
</h2>
<div class='methods'>
<h3 id='tymethod.alloc' class='method'><span id='alloc.v' class='invisible'><code>unsafe fn <a href='#tymethod.alloc' class='fnname'>alloc</a>(&self, layout: <a class="struct" href="../../core/alloc/struct.Layout.html" title="struct core::alloc::Layout">Layout</a>) -> *mut <a class="foreigntype" href="../../core/alloc/foreigntype.Opaque.html" title="foreigntype core::alloc::Opaque">Opaque</a></code></span></h3><div class='stability'><div class='stab unstable'><details><summary><span class=microscope>🔬</span> This is a nightly-only experimental API. (<code>allocator_api </code><a href="https://github.com/rust-lang/rust/issues/32838">#32838</a>)</summary><p>the precise API and guarantees it provides may be tweaked slightly, especially to possibly take into account the types being stored to make room for a future tracing garbage collector</p>
</details></div></div><div class='docblock'><p>Allocate memory as described by the given <code>layout</code>.</p>
<p>Returns a pointer to newly-allocated memory,
or NULL to indicate allocation failure.</p>
<h1 id="safety" class="section-header"><a href="#safety">Safety</a></h1>
<p><strong>FIXME:</strong> what are the exact requirements?</p>
</div><h3 id='tymethod.dealloc' class='method'><span id='dealloc.v' class='invisible'><code>unsafe fn <a href='#tymethod.dealloc' class='fnname'>dealloc</a>(&self, ptr: *mut <a class="foreigntype" href="../../core/alloc/foreigntype.Opaque.html" title="foreigntype core::alloc::Opaque">Opaque</a>, layout: <a class="struct" href="../../core/alloc/struct.Layout.html" title="struct core::alloc::Layout">Layout</a>)</code></span></h3><div class='stability'><div class='stab unstable'><details><summary><span class=microscope>🔬</span> This is a nightly-only experimental API. (<code>allocator_api </code><a href="https://github.com/rust-lang/rust/issues/32838">#32838</a>)</summary><p>the precise API and guarantees it provides may be tweaked slightly, especially to possibly take into account the types being stored to make room for a future tracing garbage collector</p>
</details></div></div><div class='docblock'><p>Deallocate the block of memory at the given <code>ptr</code> pointer with the given <code>layout</code>.</p>
<h1 id="safety-1" class="section-header"><a href="#safety-1">Safety</a></h1>
<p><strong>FIXME:</strong> what are the exact requirements?
In particular around layout <em>fit</em>. (See docs for the <code>Alloc</code> trait.)</p>
</div></div>
<h2 id='provided-methods' class='small-section-header'>
Provided Methods<a href='#provided-methods' class='anchor'></a>
</h2>
<div class='methods'>
<h3 id='method.alloc_zeroed' class='method'><span id='alloc_zeroed.v' class='invisible'><code>unsafe fn <a href='#method.alloc_zeroed' class='fnname'>alloc_zeroed</a>(&self, layout: <a class="struct" href="../../core/alloc/struct.Layout.html" title="struct core::alloc::Layout">Layout</a>) -> *mut <a class="foreigntype" href="../../core/alloc/foreigntype.Opaque.html" title="foreigntype core::alloc::Opaque">Opaque</a></code></span></h3><div class='stability'><div class='stab unstable'><details><summary><span class=microscope>🔬</span> This is a nightly-only experimental API. (<code>allocator_api </code><a href="https://github.com/rust-lang/rust/issues/32838">#32838</a>)</summary><p>the precise API and guarantees it provides may be tweaked slightly, especially to possibly take into account the types being stored to make room for a future tracing garbage collector</p>
</details></div></div><h3 id='method.realloc' class='method'><span id='realloc.v' class='invisible'><code>unsafe fn <a href='#method.realloc' class='fnname'>realloc</a>(<br> &self, <br> ptr: *mut <a class="foreigntype" href="../../core/alloc/foreigntype.Opaque.html" title="foreigntype core::alloc::Opaque">Opaque</a>, <br> layout: <a class="struct" href="../../core/alloc/struct.Layout.html" title="struct core::alloc::Layout">Layout</a>, <br> new_size: usize<br>) -> *mut <a class="foreigntype" href="../../core/alloc/foreigntype.Opaque.html" title="foreigntype core::alloc::Opaque">Opaque</a></code></span></h3><div class='stability'><div class='stab unstable'><details><summary><span class=microscope>🔬</span> This is a nightly-only experimental API. (<code>allocator_api </code><a href="https://github.com/rust-lang/rust/issues/32838">#32838</a>)</summary><p>the precise API and guarantees it provides may be tweaked slightly, especially to possibly take into account the types being stored to make room for a future tracing garbage collector</p>
</details></div></div><div class='docblock'><p>Shink or grow a block of memory to the given <code>new_size</code>.
The block is described by the given <code>ptr</code> pointer and <code>layout</code>.</p>
<p>Return a new pointer (which may or may not be the same as <code>ptr</code>),
or NULL to indicate reallocation failure.</p>
<p>If reallocation is successful, the old <code>ptr</code> pointer is considered
to have been deallocated.</p>
<h1 id="safety-2" class="section-header"><a href="#safety-2">Safety</a></h1>
<p><code>new_size</code>, when rounded up to the nearest multiple of <code>old_layout.align()</code>,
must not overflow (i.e. the rounded value must be less than <code>usize::MAX</code>).</p>
<p><strong>FIXME:</strong> what are the exact requirements?
In particular around layout <em>fit</em>. (See docs for the <code>Alloc</code> trait.)</p>
</div></div>
<h2 id='implementors' class='small-section-header'>
Implementors<a href='#implementors' class='anchor'></a>
</h2>
<ul class='item-list' id='implementors-list'>
</ul><script type="text/javascript">window.inlined_types=new Set([]);</script><script type="text/javascript" async
src="../../implementors/core/alloc/trait.GlobalAlloc.js">
</script></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>⏎</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 = "core";</script><script src="../../aliases.js"></script><script src="../../main.js"></script><script defer src="../../search-index.js"></script></body></html>
distrib
>
Mageia
>
6
>
x86_64
>
media
>
core-updates
>
by-pkgid
>
e50df336eb49b92dbadf6dedc48b7934
>
files
>
778
