<!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 `IntermediateBox` struct in crate `std`."> <meta name="keywords" content="rust, rustlang, rust-lang, IntermediateBox"> <title>std::boxed::IntermediateBox - 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="../../main.css" id="themeStyle"> <script src="../../storage.js"></script> <link rel="shortcut icon" href="https://doc.rust-lang.org/favicon.ico"> </head> <body class="rustdoc struct"> <!--[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='../../std/index.html'><img src='https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png' alt='logo' width='100'></a> <p class='location'>Struct IntermediateBox</p><div class="sidebar-elems"><div class="block items"><a class="sidebar-title" href="#implementations">Trait Implementations</a><div class="sidebar-links"><a href="#impl-BoxPlace%3CT%3E">BoxPlace<T></a><a href="#impl-InPlace%3CT%3E">InPlace<T></a><a href="#impl-Place%3CT%3E">Place<T></a><a href="#impl-Drop">Drop</a></div></div><p class='location'><a href='../index.html'>std</a>::<wbr><a href='index.html'>boxed</a></p><script>window.sidebarCurrent = {name: 'IntermediateBox', ty: 'struct', 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"> </div> </form> </nav> <section id='main' class="content"> <h1 class='fqn'><span class='in-band'>Struct <a href='../index.html'>std</a>::<wbr><a href='index.html'>boxed</a>::<wbr><a class="struct" href=''>IntermediateBox</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/alloc/boxed.rs.html#136-140' title='goto source code'>[src]</a></span></h1> <pre class='rust struct'>pub struct IntermediateBox<T> <span class="where fmt-newline">where<br> T: ?<a class="trait" href="../../std/marker/trait.Sized.html" title="trait std::marker::Sized">Sized</a>, </span> { /* fields omitted */ }</pre><div class='stability'><div class='stab unstable'><details><summary><span class=microscope>🔬</span> This is a nightly-only experimental API. (<code>placement_in </code><a href="https://github.com/rust-lang/rust/issues/27779">#27779</a>)</summary><p>placement box design is still being worked out.</p> </details></div></div><div class='docblock'><p><code>IntermediateBox</code> represents uninitialized backing storage for <code>Box</code>.</p> <p>FIXME (pnkfelix): Ideally we would just reuse <code>Box<T></code> instead of introducing a separate <code>IntermediateBox<T></code>; but then you hit issues when you e.g. attempt to destructure an instance of <code>Box</code>, since it is a lang item and so it gets special handling by the compiler. Easier just to make this parallel type for now.</p> <p>FIXME (pnkfelix): Currently the <code>box</code> protocol only supports creating instances of sized types. This IntermediateBox is designed to be forward-compatible with a future protocol that supports creating instances of unsized types; that is why the type parameter has the <code>?Sized</code> generalization marker, and is also why this carries an explicit size. However, it probably does not need to carry the explicit alignment; that is just a work-around for the fact that the <code>align_of</code> intrinsic currently requires the input type to be Sized (which I do not think is strictly necessary).</p> </div> <h2 id='implementations' class='small-section-header'> Trait Implementations<a href='#implementations' class='anchor'></a> </h2> <h3 id='impl-BoxPlace%3CT%3E' class='impl'><span class='in-band'><code>impl<T> <a class="trait" href="../../std/ops/trait.BoxPlace.html" title="trait std::ops::BoxPlace">BoxPlace</a><T> for <a class="struct" href="../../std/boxed/struct.IntermediateBox.html" title="struct std::boxed::IntermediateBox">IntermediateBox</a><T></code><a href='#impl-BoxPlace%3CT%3E' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/alloc/boxed.rs.html#180-184' title='goto source code'>[src]</a></span></h3> <div class='impl-items'><h4 id='method.make_place' class="method"><span id='make_place.v' class='invisible'><code>fn <a href='../../std/ops/trait.BoxPlace.html#tymethod.make_place' class='fnname'>make_place</a>() -> <a class="struct" href="../../std/boxed/struct.IntermediateBox.html" title="struct std::boxed::IntermediateBox">IntermediateBox</a><T></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/alloc/boxed.rs.html#181-183' title='goto source code'>[src]</a></span></h4> <div class='stability'><div class='stab unstable'><span class=microscope>🔬</span> This is a nightly-only experimental API. (<code>placement_new_protocol </code><a href="https://github.com/rust-lang/rust/issues/27779">#27779</a>)</div></div><div class='docblock'><p>Creates a globally fresh place.</p> </div></div><h3 id='impl-InPlace%3CT%3E' class='impl'><span class='in-band'><code>impl<T> <a class="trait" href="../../std/ops/trait.InPlace.html" title="trait std::ops::InPlace">InPlace</a><T> for <a class="struct" href="../../std/boxed/struct.IntermediateBox.html" title="struct std::boxed::IntermediateBox">IntermediateBox</a><T></code><a href='#impl-InPlace%3CT%3E' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/alloc/boxed.rs.html#189-194' title='goto source code'>[src]</a></span></h3> <div class='impl-items'><h4 id='associatedtype.Owner' class="type"><span id='Owner.t' class='invisible'><code>type <a href='../../std/ops/trait.InPlace.html#associatedtype.Owner' class="type">Owner</a> = <a class="struct" href="../../std/boxed/struct.Box.html" title="struct std::boxed::Box">Box</a><T></code></span></h4> <div class='stability'><div class='stab unstable'><span class=microscope>🔬</span> This is a nightly-only experimental API. (<code>placement_new_protocol </code><a href="https://github.com/rust-lang/rust/issues/27779">#27779</a>)</div></div><div class='docblock'><p><code>Owner</code> is the type of the end value of <code>PLACE <- EXPR</code> <a href="../../std/ops/trait.InPlace.html#associatedtype.Owner">Read more</a></p> </div><h4 id='method.finalize' class="method"><div class="important-traits"><div class='tooltip'>ⓘ<span class='tooltiptext'>Important traits for <a class="struct" href="../../std/boxed/struct.Box.html" title="struct std::boxed::Box">Box</a><I></span></div><div class="content hidden"><h3 class="important">Important traits for <a class="struct" href="../../std/boxed/struct.Box.html" title="struct std::boxed::Box">Box</a><I></h3><code class="content"><span class="where fmt-newline">impl<I> <a class="trait" href="../../std/iter/trait.Iterator.html" title="trait std::iter::Iterator">Iterator</a> for <a class="struct" href="../../std/boxed/struct.Box.html" title="struct std::boxed::Box">Box</a><I> <span class="where fmt-newline">where<br> I: <a class="trait" href="../../std/iter/trait.Iterator.html" title="trait std::iter::Iterator">Iterator</a> + ?<a class="trait" href="../../std/marker/trait.Sized.html" title="trait std::marker::Sized">Sized</a>, </span></span><span class="where fmt-newline"> type <a href='../../std/iter/trait.Iterator.html#associatedtype.Item' class="type">Item</a> = <I as <a class="trait" href="../../std/iter/trait.Iterator.html" title="trait std::iter::Iterator">Iterator</a>>::<a class="type" href="../../std/iter/trait.Iterator.html#associatedtype.Item" title="type std::iter::Iterator::Item">Item</a>;</span><span class="where fmt-newline">impl<R: <a class="trait" href="../../std/io/trait.Read.html" title="trait std::io::Read">Read</a> + ?<a class="trait" href="../../std/marker/trait.Sized.html" title="trait std::marker::Sized">Sized</a>> <a class="trait" href="../../std/io/trait.Read.html" title="trait std::io::Read">Read</a> for <a class="struct" href="../../std/boxed/struct.Box.html" title="struct std::boxed::Box">Box</a><R></span><span class="where fmt-newline">impl<W: <a class="trait" href="../../std/io/trait.Write.html" title="trait std::io::Write">Write</a> + ?<a class="trait" href="../../std/marker/trait.Sized.html" title="trait std::marker::Sized">Sized</a>> <a class="trait" href="../../std/io/trait.Write.html" title="trait std::io::Write">Write</a> for <a class="struct" href="../../std/boxed/struct.Box.html" title="struct std::boxed::Box">Box</a><W></span></code></div></div><span id='finalize.v' class='invisible'><code>unsafe fn <a href='../../std/ops/trait.InPlace.html#tymethod.finalize' class='fnname'>finalize</a>(self) -> <a class="struct" href="../../std/boxed/struct.Box.html" title="struct std::boxed::Box">Box</a><T></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/alloc/boxed.rs.html#191-193' title='goto source code'>[src]</a></span></h4> <div class='stability'><div class='stab unstable'><span class=microscope>🔬</span> This is a nightly-only experimental API. (<code>placement_new_protocol </code><a href="https://github.com/rust-lang/rust/issues/27779">#27779</a>)</div></div><div class='docblock'><p>Converts self into the final value, shifting deallocation/cleanup responsibilities (if any remain), over to the returned instance of <code>Owner</code> and forgetting self. <a href="../../std/ops/trait.InPlace.html#tymethod.finalize">Read more</a></p> </div></div><h3 id='impl-Place%3CT%3E' class='impl'><span class='in-band'><code>impl<T> <a class="trait" href="../../std/ops/trait.Place.html" title="trait std::ops::Place">Place</a><T> for <a class="struct" href="../../std/boxed/struct.IntermediateBox.html" title="struct std::boxed::IntermediateBox">IntermediateBox</a><T></code><a href='#impl-Place%3CT%3E' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/alloc/boxed.rs.html#145-149' title='goto source code'>[src]</a></span></h3> <div class='impl-items'><h4 id='method.pointer' class="method"><span id='pointer.v' class='invisible'><code>fn <a href='../../std/ops/trait.Place.html#tymethod.pointer' class='fnname'>pointer</a>(&mut self) -> <a class="primitive" href="../primitive.pointer.html">*mut T</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/alloc/boxed.rs.html#146-148' title='goto source code'>[src]</a></span></h4> <div class='stability'><div class='stab unstable'><span class=microscope>🔬</span> This is a nightly-only experimental API. (<code>placement_new_protocol </code><a href="https://github.com/rust-lang/rust/issues/27779">#27779</a>)</div></div><div class='docblock'><p>Returns the address where the input value will be written. Note that the data at this address is generally uninitialized, and thus one should use <code>ptr::write</code> for initializing it. <a href="../../std/ops/trait.Place.html#tymethod.pointer">Read more</a></p> </div></div><h3 id='impl-Drop' class='impl'><span class='in-band'><code>impl<T> <a class="trait" href="../../std/ops/trait.Drop.html" title="trait std::ops::Drop">Drop</a> for <a class="struct" href="../../std/boxed/struct.IntermediateBox.html" title="struct std::boxed::IntermediateBox">IntermediateBox</a><T> <span class="where fmt-newline">where<br> T: ?<a class="trait" href="../../std/marker/trait.Sized.html" title="trait std::marker::Sized">Sized</a>, </span></code><a href='#impl-Drop' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/alloc/boxed.rs.html#219-227' title='goto source code'>[src]</a></span></h3> <div class='impl-items'><h4 id='method.drop' class="method"><span id='drop.v' class='invisible'><code>fn <a href='../../std/ops/trait.Drop.html#tymethod.drop' class='fnname'>drop</a>(&mut self)</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../src/alloc/boxed.rs.html#220-226' title='goto source code'>[src]</a></span></h4> <div class='docblock'><p>Executes the destructor for this type. <a href="../../std/ops/trait.Drop.html#tymethod.drop">Read more</a></p> </div></div></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> </div> </div> </aside> <script> window.rootPath = "../../"; window.currentCrate = "std"; </script> <script src="../../main.js"></script> <script defer src="../../search-index.js"></script> </body> </html>