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<p class='location'>Trait IntoIterator</p><div class="block items"><ul><li><a href="#associated-types">Associated Types</a></li><li><a href="#required-methods">Required Methods</a></li><li><a href="#implementors">Implementors</a></li></ul></div><p class='location'><a href='../index.html'>core</a>::<wbr><a href='index.html'>iter</a></p><script>window.sidebarCurrent = {name: 'IntoIterator', ty: 'trait', relpath: ''};</script><script defer src="sidebar-items.js"></script>
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<h1 class='fqn'><span class='in-band'>Trait <a href='../index.html'>core</a>::<wbr><a href='index.html'>iter</a>::<wbr><a class="trait" href=''>IntoIterator</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'>
<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/iter/traits.rs.html#209-247' title='goto source code'>[src]</a></span></h1>
<pre class='rust trait'>pub trait IntoIterator {
type <a href='#associatedtype.Item' class="type">Item</a>;
type <a href='#associatedtype.IntoIter' class="type">IntoIter</a>: <a class="trait" href="../../core/iter/trait.Iterator.html" title="trait core::iter::Iterator">Iterator</a><Item = Self::<a class="trait" href="../../core/iter/trait.IntoIterator.html" title="trait core::iter::IntoIterator">Item</a>>;
fn <a href='#tymethod.into_iter' class='fnname'>into_iter</a>(self) -> Self::<a class="trait" href="../../core/iter/trait.IntoIterator.html" title="trait core::iter::IntoIterator">IntoIter</a>;
}</pre><div class='docblock'><p>Conversion into an <code>Iterator</code>.</p>
<p>By implementing <code>IntoIterator</code> for a type, you define how it will be
converted to an iterator. This is common for types which describe a
collection of some kind.</p>
<p>One benefit of implementing <code>IntoIterator</code> is that your type will <a href="index.html#for-loops-and-intoiterator">work
with Rust's <code>for</code> loop syntax</a>.</p>
<p>See also: <a href="trait.FromIterator.html"><code>FromIterator</code></a>.</p>
<h1 id='examples' class='section-header'><a href='#examples'>Examples</a></h1>
<p>Basic usage:</p>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">v</span> <span class="op">=</span> <span class="macro">vec</span><span class="macro">!</span>[<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>];
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">iter</span> <span class="op">=</span> <span class="ident">v</span>.<span class="ident">into_iter</span>();
<span class="kw">let</span> <span class="ident">n</span> <span class="op">=</span> <span class="ident">iter</span>.<span class="ident">next</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">Some</span>(<span class="number">1</span>), <span class="ident">n</span>);
<span class="kw">let</span> <span class="ident">n</span> <span class="op">=</span> <span class="ident">iter</span>.<span class="ident">next</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">Some</span>(<span class="number">2</span>), <span class="ident">n</span>);
<span class="kw">let</span> <span class="ident">n</span> <span class="op">=</span> <span class="ident">iter</span>.<span class="ident">next</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">Some</span>(<span class="number">3</span>), <span class="ident">n</span>);
<span class="kw">let</span> <span class="ident">n</span> <span class="op">=</span> <span class="ident">iter</span>.<span class="ident">next</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">None</span>, <span class="ident">n</span>);<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=fn%20main()%20%7B%0Alet%20v%20%3D%20vec!%5B1%2C%202%2C%203%5D%3B%0A%0Alet%20mut%20iter%20%3D%20v.into_iter()%3B%0A%0Alet%20n%20%3D%20iter.next()%3B%0Aassert_eq!(Some(1)%2C%20n)%3B%0A%0Alet%20n%20%3D%20iter.next()%3B%0Aassert_eq!(Some(2)%2C%20n)%3B%0A%0Alet%20n%20%3D%20iter.next()%3B%0Aassert_eq!(Some(3)%2C%20n)%3B%0A%0Alet%20n%20%3D%20iter.next()%3B%0Aassert_eq!(None%2C%20n)%3B%0A%7D">Run</a></pre>
<p>Implementing <code>IntoIterator</code> for your type:</p>
<pre class="rust rust-example-rendered">
<span class="comment">// A sample collection, that's just a wrapper over Vec<T></span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>)]</span>
<span class="kw">struct</span> <span class="ident">MyCollection</span>(<span class="ident">Vec</span><span class="op"><</span><span class="ident">i32</span><span class="op">></span>);
<span class="comment">// Let's give it some methods so we can create one and add things</span>
<span class="comment">// to it.</span>
<span class="kw">impl</span> <span class="ident">MyCollection</span> {
<span class="kw">fn</span> <span class="ident">new</span>() <span class="op">-></span> <span class="ident">MyCollection</span> {
<span class="ident">MyCollection</span>(<span class="ident">Vec</span>::<span class="ident">new</span>())
}
<span class="kw">fn</span> <span class="ident">add</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">elem</span>: <span class="ident">i32</span>) {
<span class="self">self</span>.<span class="number">0</span>.<span class="ident">push</span>(<span class="ident">elem</span>);
}
}
<span class="comment">// and we'll implement IntoIterator</span>
<span class="kw">impl</span> <span class="ident">IntoIterator</span> <span class="kw">for</span> <span class="ident">MyCollection</span> {
<span class="kw">type</span> <span class="ident">Item</span> <span class="op">=</span> <span class="ident">i32</span>;
<span class="kw">type</span> <span class="ident">IntoIter</span> <span class="op">=</span> ::<span class="ident">std</span>::<span class="ident">vec</span>::<span class="ident">IntoIter</span><span class="op"><</span><span class="ident">i32</span><span class="op">></span>;
<span class="kw">fn</span> <span class="ident">into_iter</span>(<span class="self">self</span>) <span class="op">-></span> <span class="self">Self</span>::<span class="ident">IntoIter</span> {
<span class="self">self</span>.<span class="number">0</span>.<span class="ident">into_iter</span>()
}
}
<span class="comment">// Now we can make a new collection...</span>
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">c</span> <span class="op">=</span> <span class="ident">MyCollection</span>::<span class="ident">new</span>();
<span class="comment">// ... add some stuff to it ...</span>
<span class="ident">c</span>.<span class="ident">add</span>(<span class="number">0</span>);
<span class="ident">c</span>.<span class="ident">add</span>(<span class="number">1</span>);
<span class="ident">c</span>.<span class="ident">add</span>(<span class="number">2</span>);
<span class="comment">// ... and then turn it into an Iterator:</span>
<span class="kw">for</span> (<span class="ident">i</span>, <span class="ident">n</span>) <span class="kw">in</span> <span class="ident">c</span>.<span class="ident">into_iter</span>().<span class="ident">enumerate</span>() {
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">i</span> <span class="kw">as</span> <span class="ident">i32</span>, <span class="ident">n</span>);
}<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=fn%20main()%20%7B%0A%2F%2F%20A%20sample%20collection%2C%20that's%20just%20a%20wrapper%20over%20Vec%3CT%3E%0A%23%5Bderive(Debug)%5D%0Astruct%20MyCollection(Vec%3Ci32%3E)%3B%0A%0A%2F%2F%20Let's%20give%20it%20some%20methods%20so%20we%20can%20create%20one%20and%20add%20things%0A%2F%2F%20to%20it.%0Aimpl%20MyCollection%20%7B%0A%20%20%20%20fn%20new()%20-%3E%20MyCollection%20%7B%0A%20%20%20%20%20%20%20%20MyCollection(Vec%3A%3Anew())%0A%20%20%20%20%7D%0A%0A%20%20%20%20fn%20add(%26mut%20self%2C%20elem%3A%20i32)%20%7B%0A%20%20%20%20%20%20%20%20self.0.push(elem)%3B%0A%20%20%20%20%7D%0A%7D%0A%0A%2F%2F%20and%20we'll%20implement%20IntoIterator%0Aimpl%20IntoIterator%20for%20MyCollection%20%7B%0A%20%20%20%20type%20Item%20%3D%20i32%3B%0A%20%20%20%20type%20IntoIter%20%3D%20%3A%3Astd%3A%3Avec%3A%3AIntoIter%3Ci32%3E%3B%0A%0A%20%20%20%20fn%20into_iter(self)%20-%3E%20Self%3A%3AIntoIter%20%7B%0A%20%20%20%20%20%20%20%20self.0.into_iter()%0A%20%20%20%20%7D%0A%7D%0A%0A%2F%2F%20Now%20we%20can%20make%20a%20new%20collection...%0Alet%20mut%20c%20%3D%20MyCollection%3A%3Anew()%3B%0A%0A%2F%2F%20...%20add%20some%20stuff%20to%20it%20...%0Ac.add(0)%3B%0Ac.add(1)%3B%0Ac.add(2)%3B%0A%0A%2F%2F%20...%20and%20then%20turn%20it%20into%20an%20Iterator%3A%0Afor%20(i%2C%20n)%20in%20c.into_iter().enumerate()%20%7B%0A%20%20%20%20assert_eq!(i%20as%20i32%2C%20n)%3B%0A%7D%0A%7D">Run</a></pre>
</div>
<h2 id='associated-types'>Associated Types</h2>
<div class='methods'>
<h3 id='associatedtype.Item' class='method'><span id='Item.t' class='invisible'><code>type <a href='#associatedtype.Item' class="type">Item</a></code></span></h3><div class='docblock'><p>The type of the elements being iterated over.</p>
</div><h3 id='associatedtype.IntoIter' class='method'><span id='IntoIter.t' class='invisible'><code>type <a href='#associatedtype.IntoIter' class="type">IntoIter</a>: <a class="trait" href="../../core/iter/trait.Iterator.html" title="trait core::iter::Iterator">Iterator</a><Item = Self::<a class="trait" href="../../core/iter/trait.IntoIterator.html" title="trait core::iter::IntoIterator">Item</a>></code></span></h3><div class='docblock'><p>Which kind of iterator are we turning this into?</p>
</div></div>
<h2 id='required-methods'>Required Methods</h2>
<div class='methods'>
<h3 id='tymethod.into_iter' class='method'><span id='into_iter.v' class='invisible'><code>fn <a href='#tymethod.into_iter' class='fnname'>into_iter</a>(self) -> Self::<a class="trait" href="../../core/iter/trait.IntoIterator.html" title="trait core::iter::IntoIterator">IntoIter</a></code></span></h3><div class='docblock'><p>Creates an iterator from a value.</p>
<p>See the <a href="index.html">module-level documentation</a> for more.</p>
<h1 id='examples-1' class='section-header'><a href='#examples-1'>Examples</a></h1>
<p>Basic usage:</p>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">v</span> <span class="op">=</span> <span class="macro">vec</span><span class="macro">!</span>[<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>];
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">iter</span> <span class="op">=</span> <span class="ident">v</span>.<span class="ident">into_iter</span>();
<span class="kw">let</span> <span class="ident">n</span> <span class="op">=</span> <span class="ident">iter</span>.<span class="ident">next</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">Some</span>(<span class="number">1</span>), <span class="ident">n</span>);
<span class="kw">let</span> <span class="ident">n</span> <span class="op">=</span> <span class="ident">iter</span>.<span class="ident">next</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">Some</span>(<span class="number">2</span>), <span class="ident">n</span>);
<span class="kw">let</span> <span class="ident">n</span> <span class="op">=</span> <span class="ident">iter</span>.<span class="ident">next</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">Some</span>(<span class="number">3</span>), <span class="ident">n</span>);
<span class="kw">let</span> <span class="ident">n</span> <span class="op">=</span> <span class="ident">iter</span>.<span class="ident">next</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">None</span>, <span class="ident">n</span>);<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=fn%20main()%20%7B%0Alet%20v%20%3D%20vec!%5B1%2C%202%2C%203%5D%3B%0A%0Alet%20mut%20iter%20%3D%20v.into_iter()%3B%0A%0Alet%20n%20%3D%20iter.next()%3B%0Aassert_eq!(Some(1)%2C%20n)%3B%0A%0Alet%20n%20%3D%20iter.next()%3B%0Aassert_eq!(Some(2)%2C%20n)%3B%0A%0Alet%20n%20%3D%20iter.next()%3B%0Aassert_eq!(Some(3)%2C%20n)%3B%0A%0Alet%20n%20%3D%20iter.next()%3B%0Aassert_eq!(None%2C%20n)%3B%0A%7D">Run</a></pre>
</div></div>
<h2 id='implementors'>Implementors</h2>
<ul class='item-list' id='implementors-list'>
<li><code>impl<'a, T> IntoIterator for &'a [T; 0]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 0]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 1]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 1]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 2]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 2]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 3]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 3]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 4]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 4]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 5]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 5]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 6]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 6]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 7]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 7]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 8]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 8]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 9]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 9]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 10]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 10]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 11]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 11]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 12]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 12]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 13]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 13]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 14]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 14]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 15]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 15]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 16]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 16]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 17]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 17]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 18]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 18]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 19]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 19]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 20]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 20]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 21]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 21]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 22]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 22]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 23]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 23]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 24]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 24]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 25]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 25]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 26]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 26]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 27]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 27]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 28]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 28]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 29]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 29]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 30]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 30]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 31]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 31]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T; 32]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T; 32]</code></li>
<li><code>impl<I: <a class="trait" href="../../core/iter/trait.Iterator.html" title="trait core::iter::Iterator">Iterator</a>> IntoIterator for I</code></li>
<li><code>impl<T> IntoIterator for <a class="enum" href="../../core/option/enum.Option.html" title="enum core::option::Option">Option</a><T></code></li>
<li><code>impl<'a, T> IntoIterator for &'a <a class="enum" href="../../core/option/enum.Option.html" title="enum core::option::Option">Option</a><T></code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut <a class="enum" href="../../core/option/enum.Option.html" title="enum core::option::Option">Option</a><T></code></li>
<li><code>impl<T, E> IntoIterator for <a class="enum" href="../../core/result/enum.Result.html" title="enum core::result::Result">Result</a><T, E></code></li>
<li><code>impl<'a, T, E> IntoIterator for &'a <a class="enum" href="../../core/result/enum.Result.html" title="enum core::result::Result">Result</a><T, E></code></li>
<li><code>impl<'a, T, E> IntoIterator for &'a mut <a class="enum" href="../../core/result/enum.Result.html" title="enum core::result::Result">Result</a><T, E></code></li>
<li><code>impl<'a, T> IntoIterator for &'a [T]</code></li>
<li><code>impl<'a, T> IntoIterator for &'a mut [T]</code></li>
</ul><script type="text/javascript" async
src="../../implementors/core/iter/trait.IntoIterator.js">
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