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<p class='location'>Struct VacantEntry</p><div class="sidebar-elems"><div class="block items"><a class="sidebar-title" href="#methods">Methods</a><div class="sidebar-links"><a href="#method.key">key</a><a href="#method.into_key">into_key</a><a href="#method.insert">insert</a></div><a class="sidebar-title" href="#implementations">Trait Implementations</a><div class="sidebar-links"><a href="#impl-Debug">Debug</a></div></div><p class='location'><a href='../../index.html'>std</a>::<wbr><a href='../index.html'>collections</a>::<wbr><a href='index.html'>hash_map</a></p><script>window.sidebarCurrent = {name: 'VacantEntry', ty: 'struct', relpath: ''};</script><script defer src="sidebar-items.js"></script></div>
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<h1 class='fqn'><span class='in-band'>Struct <a href='../../index.html'>std</a>::<wbr><a href='../index.html'>collections</a>::<wbr><a href='index.html'>hash_map</a>::<wbr><a class="struct" href=''>VacantEntry</a></span><span class='out-of-band'><span class='since' title='Stable since Rust version 1.0.0'>1.0.0</span><span id='render-detail'>
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</span><a class='srclink' href='../../../src/std/collections/hash/map.rs.html#1636-1640' title='goto source code'>[src]</a></span></h1>
<pre class='rust struct'>pub struct VacantEntry<'a, K: 'a, V: 'a> { /* fields omitted */ }</pre><div class='docblock'><p>A view into a vacant entry in a <code>HashMap</code>.
It is part of the <a href="enum.Entry.html"><code>Entry</code></a> enum.</p>
</div>
<h2 id='methods' class='small-section-header'>
Methods<a href='#methods' class='anchor'></a>
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<h3 id='impl' class='impl'><span class='in-band'><code>impl<'a, K: 'a, V: 'a> <a class="struct" href="../../../std/collections/hash_map/struct.VacantEntry.html" title="struct std::collections::hash_map::VacantEntry">VacantEntry</a><'a, K, V></code><a href='#impl' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../../src/std/collections/hash/map.rs.html#2350-2440' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.key' class="method"><div class="important-traits"><div class='tooltip'>ⓘ<span class='tooltiptext'>Important traits for <a class="primitive" href="../../primitive.reference.html">&'a mut </a>I</span></div><div class="content hidden"><h3 class="important">Important traits for <a class="primitive" href="../../primitive.reference.html">&'a mut </a>I</h3><code class="content"><span class="where fmt-newline">impl<'a, I> <a class="trait" href="../../../std/iter/trait.Iterator.html" title="trait std::iter::Iterator">Iterator</a> for <a class="primitive" href="../../primitive.reference.html">&'a mut </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<'a, 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="primitive" href="../../primitive.reference.html">&'a mut </a>R</span><span class="where fmt-newline">impl<'a, 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="primitive" href="../../primitive.reference.html">&'a mut </a>W</span></code></div></div><span id='key.v' class='invisible'><code>pub fn <a href='#method.key' class='fnname'>key</a>(&self) -> <a class="primitive" href="../../primitive.reference.html">&</a>K</code></span><span class='out-of-band'><div class='ghost'></div><div class='since' title='Stable since Rust version 1.10.0'>1.10.0</div><a class='srclink' href='../../../src/std/collections/hash/map.rs.html#2363-2365' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Gets a reference to the key that would be used when inserting a value
through the <code>VacantEntry</code>.</p>
<h1 id="examples" class="section-header"><a href="#examples">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">collections</span>::<span class="ident">HashMap</span>;
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">map</span>: <span class="ident">HashMap</span><span class="op"><</span><span class="kw-2">&</span><span class="ident">str</span>, <span class="ident">u32</span><span class="op">></span> <span class="op">=</span> <span class="ident">HashMap</span>::<span class="ident">new</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">map</span>.<span class="ident">entry</span>(<span class="string">"poneyland"</span>).<span class="ident">key</span>(), <span class="kw-2">&</span><span class="string">"poneyland"</span>);<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=%23!%5Ballow(unused)%5D%0Afn%20main()%20%7B%0Ause%20std%3A%3Acollections%3A%3AHashMap%3B%0A%0Alet%20mut%20map%3A%20HashMap%3C%26str%2C%20u32%3E%20%3D%20HashMap%3A%3Anew()%3B%0Aassert_eq!(map.entry(%22poneyland%22).key()%2C%20%26%22poneyland%22)%3B%0A%7D">Run</a></pre>
</div><h4 id='method.into_key' class="method"><span id='into_key.v' class='invisible'><code>pub fn <a href='#method.into_key' class='fnname'>into_key</a>(self) -> K</code></span><span class='out-of-band'><div class='ghost'></div><div class='since' title='Stable since Rust version 1.12.0'>1.12.0</div><a class='srclink' href='../../../src/std/collections/hash/map.rs.html#2382-2384' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Take ownership of the key.</p>
<h1 id="examples-1" class="section-header"><a href="#examples-1">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">collections</span>::<span class="ident">HashMap</span>;
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">collections</span>::<span class="ident">hash_map</span>::<span class="ident">Entry</span>;
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">map</span>: <span class="ident">HashMap</span><span class="op"><</span><span class="kw-2">&</span><span class="ident">str</span>, <span class="ident">u32</span><span class="op">></span> <span class="op">=</span> <span class="ident">HashMap</span>::<span class="ident">new</span>();
<span class="kw">if</span> <span class="kw">let</span> <span class="ident">Entry</span>::<span class="ident">Vacant</span>(<span class="ident">v</span>) <span class="op">=</span> <span class="ident">map</span>.<span class="ident">entry</span>(<span class="string">"poneyland"</span>) {
<span class="ident">v</span>.<span class="ident">into_key</span>();
}<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=%23!%5Ballow(unused)%5D%0Afn%20main()%20%7B%0Ause%20std%3A%3Acollections%3A%3AHashMap%3B%0Ause%20std%3A%3Acollections%3A%3Ahash_map%3A%3AEntry%3B%0A%0Alet%20mut%20map%3A%20HashMap%3C%26str%2C%20u32%3E%20%3D%20HashMap%3A%3Anew()%3B%0A%0Aif%20let%20Entry%3A%3AVacant(v)%20%3D%20map.entry(%22poneyland%22)%20%7B%0A%20%20%20%20v.into_key()%3B%0A%7D%0A%7D">Run</a></pre>
</div><h4 id='method.insert' class="method"><div class="important-traits"><div class='tooltip'>ⓘ<span class='tooltiptext'>Important traits for <a class="primitive" href="../../primitive.reference.html">&'a mut </a>I</span></div><div class="content hidden"><h3 class="important">Important traits for <a class="primitive" href="../../primitive.reference.html">&'a mut </a>I</h3><code class="content"><span class="where fmt-newline">impl<'a, I> <a class="trait" href="../../../std/iter/trait.Iterator.html" title="trait std::iter::Iterator">Iterator</a> for <a class="primitive" href="../../primitive.reference.html">&'a mut </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<'a, 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="primitive" href="../../primitive.reference.html">&'a mut </a>R</span><span class="where fmt-newline">impl<'a, 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="primitive" href="../../primitive.reference.html">&'a mut </a>W</span></code></div></div><span id='insert.v' class='invisible'><code>pub fn <a href='#method.insert' class='fnname'>insert</a>(self, value: V) -> <a class="primitive" href="../../primitive.reference.html">&'a mut </a>V</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../../src/std/collections/hash/map.rs.html#2403-2419' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Sets the value of the entry with the VacantEntry's key,
and returns a mutable reference to it.</p>
<h1 id="examples-2" class="section-header"><a href="#examples-2">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">collections</span>::<span class="ident">HashMap</span>;
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">collections</span>::<span class="ident">hash_map</span>::<span class="ident">Entry</span>;
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">map</span>: <span class="ident">HashMap</span><span class="op"><</span><span class="kw-2">&</span><span class="ident">str</span>, <span class="ident">u32</span><span class="op">></span> <span class="op">=</span> <span class="ident">HashMap</span>::<span class="ident">new</span>();
<span class="kw">if</span> <span class="kw">let</span> <span class="ident">Entry</span>::<span class="ident">Vacant</span>(<span class="ident">o</span>) <span class="op">=</span> <span class="ident">map</span>.<span class="ident">entry</span>(<span class="string">"poneyland"</span>) {
<span class="ident">o</span>.<span class="ident">insert</span>(<span class="number">37</span>);
}
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">map</span>[<span class="string">"poneyland"</span>], <span class="number">37</span>);<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=%23!%5Ballow(unused)%5D%0Afn%20main()%20%7B%0Ause%20std%3A%3Acollections%3A%3AHashMap%3B%0Ause%20std%3A%3Acollections%3A%3Ahash_map%3A%3AEntry%3B%0A%0Alet%20mut%20map%3A%20HashMap%3C%26str%2C%20u32%3E%20%3D%20HashMap%3A%3Anew()%3B%0A%0Aif%20let%20Entry%3A%3AVacant(o)%20%3D%20map.entry(%22poneyland%22)%20%7B%0A%20%20%20%20o.insert(37)%3B%0A%7D%0Aassert_eq!(map%5B%22poneyland%22%5D%2C%2037)%3B%0A%7D">Run</a></pre>
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<h2 id='implementations' class='small-section-header'>
Trait Implementations<a href='#implementations' class='anchor'></a>
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<h3 id='impl-Debug' class='impl'><span class='in-band'><code>impl<'a, K: 'a + <a class="trait" href="../../../std/fmt/trait.Debug.html" title="trait std::fmt::Debug">Debug</a>, V: 'a> <a class="trait" href="../../../std/fmt/trait.Debug.html" title="trait std::fmt::Debug">Debug</a> for <a class="struct" href="../../../std/collections/hash_map/struct.VacantEntry.html" title="struct std::collections::hash_map::VacantEntry">VacantEntry</a><'a, K, V></code><a href='#impl-Debug' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><div class='since' title='Stable since Rust version 1.12.0'>1.12.0</div><a class='srclink' href='../../../src/std/collections/hash/map.rs.html#1643-1649' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.fmt' class="method"><span id='fmt.v' class='invisible'><code>fn <a href='../../../std/fmt/trait.Debug.html#tymethod.fmt' class='fnname'>fmt</a>(&self, f: &mut <a class="struct" href="../../../std/fmt/struct.Formatter.html" title="struct std::fmt::Formatter">Formatter</a>) -> <a class="type" href="../../../std/fmt/type.Result.html" title="type std::fmt::Result">Result</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='../../../src/std/collections/hash/map.rs.html#1644-1648' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Formats the value using the given formatter. <a href="../../../std/fmt/trait.Debug.html#tymethod.fmt">Read more</a></p>
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