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        <p class='location'>Enum Option</p><div class="sidebar-elems"><div class="block items"><a class="sidebar-title" href="#variants">Variants</a><div class="sidebar-links"><a href="#variant.None">None</a><a href="#variant.Some">Some</a></div><a class="sidebar-title" href="#methods">Methods</a><div class="sidebar-links"><a href="#method.is_some">is_some</a><a href="#method.is_none">is_none</a><a href="#method.as_ref">as_ref</a><a href="#method.as_mut">as_mut</a><a href="#method.expect">expect</a><a href="#method.unwrap">unwrap</a><a href="#method.unwrap_or">unwrap_or</a><a href="#method.unwrap_or_else">unwrap_or_else</a><a href="#method.map">map</a><a href="#method.map_or">map_or</a><a href="#method.map_or_else">map_or_else</a><a href="#method.ok_or">ok_or</a><a href="#method.ok_or_else">ok_or_else</a><a href="#method.iter">iter</a><a href="#method.iter_mut">iter_mut</a><a href="#method.and">and</a><a href="#method.and_then">and_then</a><a href="#method.filter">filter</a><a href="#method.or">or</a><a href="#method.or_else">or_else</a><a href="#method.get_or_insert">get_or_insert</a><a href="#method.get_or_insert_with">get_or_insert_with</a><a href="#method.take">take</a><a href="#method.cloned">cloned</a><a href="#method.cloned">cloned</a><a href="#method.unwrap_or_default">unwrap_or_default</a><a href="#method.transpose">transpose</a></div><a class="sidebar-title" href="#implementations">Trait Implementations</a><div class="sidebar-links"><a href="#impl-Debug">Debug</a><a href="#impl-IntoIterator">IntoIterator</a><a href="#impl-FromIterator%3COption%3CA%3E%3E">FromIterator&lt;Option&lt;A&gt;&gt;</a><a href="#impl-Hash">Hash</a><a href="#impl-Default">Default</a><a href="#impl-Clone">Clone</a><a href="#impl-PartialOrd%3COption%3CT%3E%3E">PartialOrd&lt;Option&lt;T&gt;&gt;</a><a href="#impl-Ord">Ord</a><a href="#impl-Eq">Eq</a><a href="#impl-PartialEq%3COption%3CT%3E%3E">PartialEq&lt;Option&lt;T&gt;&gt;</a><a href="#impl-Try">Try</a><a href="#impl-From%3CT%3E">From&lt;T&gt;</a><a href="#impl-Copy">Copy</a></div></div><p class='location'><a href='index.html'>enum_primitive</a></p><script>window.sidebarCurrent = {name: 'Option', ty: 'enum', relpath: ''};</script><script defer src="sidebar-items.js"></script></div>
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<h1 class='fqn'><span class='in-band'>Enum <a href='index.html'>enum_primitive</a>::<wbr><a class="enum" href=''>Option</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'>&#x2212;</span>]
                   </a>
               </span><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#159-166' title='goto source code'>[src]</a></span></h1>
<pre class='rust enum'>pub enum Option&lt;T&gt; {
    None,
    Some(T),
}</pre><div class='docblock'><p>The <code>Option</code> type. See <a href="index.html">the module level documentation</a> for more.</p>
</div><h2 id='variants' class='variants small-section-header'>
                   Variants<a href='#variants' class='anchor'></a></h2>
<span id="variant.None" class="variant small-section-header"><a href="#variant.None" class="anchor field"></a><span id='None.v' class='invisible'><code>None</code></span></span><div class='docblock'><p>No value</p>
</div><span id="variant.Some" class="variant small-section-header"><a href="#variant.Some" class="anchor field"></a><span id='Some.v' class='invisible'><code>Some(T)</code></span></span><div class='docblock'><p>Some value <code>T</code></p>
</div>
                    <h2 id='methods' class='small-section-header'>
                      Methods<a href='#methods' class='anchor'></a>
                    </h2>
                <h3 id='impl' class='impl'><span class='in-band'><code>impl&lt;T&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code><a href='#impl' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#172-804' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.is_some' class="method"><span id='is_some.v' class='invisible'><code>pub fn <a href='#method.is_some' class='fnname'>is_some</a>(&amp;self) -&gt; <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#192-197' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Returns <code>true</code> if the option is a <a href="#variant.Some"><code>Some</code></a> value.</p>
<h1 id="examples" class="section-header"><a href="#examples">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">u32</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="number">2</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">is_some</span>(), <span class="bool-val">true</span>);

<span class="kw">let</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">u32</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">is_some</span>(), <span class="bool-val">false</span>);</pre>
</div><h4 id='method.is_none' class="method"><span id='is_none.v' class='invisible'><code>pub fn <a href='#method.is_none' class='fnname'>is_none</a>(&amp;self) -&gt; <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#214-216' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Returns <code>true</code> if the option is a <a href="#variant.None"><code>None</code></a> value.</p>
<h1 id="examples-1" class="section-header"><a href="#examples-1">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">u32</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="number">2</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">is_none</span>(), <span class="bool-val">false</span>);

<span class="kw">let</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">u32</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">is_none</span>(), <span class="bool-val">true</span>);</pre>
</div><h4 id='method.as_ref' class="method"><span id='as_ref.v' class='invisible'><code>pub fn <a href='#method.as_ref' class='fnname'>as_ref</a>(&amp;self) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;</a>T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#244-249' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Converts from <code>Option&lt;T&gt;</code> to <code>Option&lt;&amp;T&gt;</code>.</p>
<h1 id="examples-2" class="section-header"><a href="#examples-2">Examples</a></h1>
<p>Convert an <code>Option&lt;</code><a href="../../std/string/struct.String.html"><code>String</code></a><code>&gt;</code> into an <code>Option&lt;</code><a href="../../std/primitive.usize.html"><code>usize</code></a><code>&gt;</code>, preserving the original.
The <a href="enum.Option.html#method.map"><code>map</code></a> method takes the <code>self</code> argument by value, consuming the original,
so this technique uses <code>as_ref</code> to first take an <code>Option</code> to a reference
to the value inside the original.</p>

<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">num_as_str</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">String</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="string">&quot;10&quot;</span>.<span class="ident">to_string</span>());
<span class="comment">// First, cast `Option&lt;String&gt;` to `Option&lt;&amp;String&gt;` with `as_ref`,</span>
<span class="comment">// then consume *that* with `map`, leaving `num_as_str` on the stack.</span>
<span class="kw">let</span> <span class="ident">num_as_int</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">usize</span><span class="op">&gt;</span> <span class="op">=</span> <span class="ident">num_as_str</span>.<span class="ident">as_ref</span>().<span class="ident">map</span>(<span class="op">|</span><span class="ident">n</span><span class="op">|</span> <span class="ident">n</span>.<span class="ident">len</span>());
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;still can print num_as_str: {:?}&quot;</span>, <span class="ident">num_as_str</span>);</pre>
</div><h4 id='method.as_mut' class="method"><span id='as_mut.v' class='invisible'><code>pub fn <a href='#method.as_mut' class='fnname'>as_mut</a>(&amp;mut self) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;mut </a>T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#265-270' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Converts from <code>Option&lt;T&gt;</code> to <code>Option&lt;&amp;mut T&gt;</code>.</p>
<h1 id="examples-3" class="section-header"><a href="#examples-3">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="number">2</span>);
<span class="kw">match</span> <span class="ident">x</span>.<span class="ident">as_mut</span>() {
    <span class="prelude-val">Some</span>(<span class="ident">v</span>) <span class="op">=&gt;</span> <span class="kw-2">*</span><span class="ident">v</span> <span class="op">=</span> <span class="number">42</span>,
    <span class="prelude-val">None</span> <span class="op">=&gt;</span> {},
}
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>, <span class="prelude-val">Some</span>(<span class="number">42</span>));</pre>
</div><h4 id='method.expect' class="method"><span id='expect.v' class='invisible'><code>pub fn <a href='#method.expect' class='fnname'>expect</a>(self, msg: &amp;<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a>) -&gt; T</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#299-304' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Unwraps an option, yielding the content of a <a href="#variant.Some"><code>Some</code></a>.</p>
<h1 id="panics" class="section-header"><a href="#panics">Panics</a></h1>
<p>Panics if the value is a <a href="#variant.None"><code>None</code></a> with a custom panic message provided by
<code>msg</code>.</p>
<h1 id="examples-4" class="section-header"><a href="#examples-4">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="string">&quot;value&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">expect</span>(<span class="string">&quot;the world is ending&quot;</span>), <span class="string">&quot;value&quot;</span>);</pre>

<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="kw-2">&amp;</span><span class="ident">str</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="ident">x</span>.<span class="ident">expect</span>(<span class="string">&quot;the world is ending&quot;</span>); <span class="comment">// panics with `the world is ending`</span></pre>
</div><h4 id='method.unwrap' class="method"><span id='unwrap.v' class='invisible'><code>pub fn <a href='#method.unwrap' class='fnname'>unwrap</a>(self) -&gt; T</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#332-337' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Moves the value <code>v</code> out of the <code>Option&lt;T&gt;</code> if it is <a href="#variant.Some"><code>Some(v)</code></a>.</p>
<p>In general, because this function may panic, its use is discouraged.
Instead, prefer to use pattern matching and handle the <a href="#variant.None"><code>None</code></a>
case explicitly.</p>
<h1 id="panics-1" class="section-header"><a href="#panics-1">Panics</a></h1>
<p>Panics if the self value equals <a href="#variant.None"><code>None</code></a>.</p>
<h1 id="examples-5" class="section-header"><a href="#examples-5">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="string">&quot;air&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">unwrap</span>(), <span class="string">&quot;air&quot;</span>);</pre>

<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="kw-2">&amp;</span><span class="ident">str</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">unwrap</span>(), <span class="string">&quot;air&quot;</span>); <span class="comment">// fails</span></pre>
</div><h4 id='method.unwrap_or' class="method"><span id='unwrap_or.v' class='invisible'><code>pub fn <a href='#method.unwrap_or' class='fnname'>unwrap_or</a>(self, def: T) -&gt; T</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#355-360' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Returns the contained value or a default.</p>
<p>Arguments passed to <code>unwrap_or</code> are eagerly evaluated; if you are passing
the result of a function call, it is recommended to use <a href="#method.unwrap_or_else"><code>unwrap_or_else</code></a>,
which is lazily evaluated.</p>
<h1 id="examples-6" class="section-header"><a href="#examples-6">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">Some</span>(<span class="string">&quot;car&quot;</span>).<span class="ident">unwrap_or</span>(<span class="string">&quot;bike&quot;</span>), <span class="string">&quot;car&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">None</span>.<span class="ident">unwrap_or</span>(<span class="string">&quot;bike&quot;</span>), <span class="string">&quot;bike&quot;</span>);</pre>
</div><h4 id='method.unwrap_or_else' class="method"><span id='unwrap_or_else.v' class='invisible'><code>pub fn <a href='#method.unwrap_or_else' class='fnname'>unwrap_or_else</a>&lt;F&gt;(self, f: F) -&gt; T <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>() -&gt; T,&nbsp;</span></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#373-378' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Returns the contained value or computes it from a closure.</p>
<h1 id="examples-7" class="section-header"><a href="#examples-7">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">k</span> <span class="op">=</span> <span class="number">10</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">Some</span>(<span class="number">4</span>).<span class="ident">unwrap_or_else</span>(<span class="op">||</span> <span class="number">2</span> <span class="op">*</span> <span class="ident">k</span>), <span class="number">4</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">None</span>.<span class="ident">unwrap_or_else</span>(<span class="op">||</span> <span class="number">2</span> <span class="op">*</span> <span class="ident">k</span>), <span class="number">20</span>);</pre>
</div><h4 id='method.map' class="method"><span id='map.v' class='invisible'><code>pub fn <a href='#method.map' class='fnname'>map</a>&lt;U, F&gt;(self, f: F) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;U&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>(T) -&gt; U,&nbsp;</span></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#402-407' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Maps an <code>Option&lt;T&gt;</code> to <code>Option&lt;U&gt;</code> by applying a function to a contained value.</p>
<h1 id="examples-8" class="section-header"><a href="#examples-8">Examples</a></h1>
<p>Convert an <code>Option&lt;</code><a href="../../std/string/struct.String.html"><code>String</code></a><code>&gt;</code> into an <code>Option&lt;</code><a href="../../std/primitive.usize.html"><code>usize</code></a><code>&gt;</code>, consuming the original:</p>

<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">maybe_some_string</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="ident">String</span>::<span class="ident">from</span>(<span class="string">&quot;Hello, World!&quot;</span>));
<span class="comment">// `Option::map` takes self *by value*, consuming `maybe_some_string`</span>
<span class="kw">let</span> <span class="ident">maybe_some_len</span> <span class="op">=</span> <span class="ident">maybe_some_string</span>.<span class="ident">map</span>(<span class="op">|</span><span class="ident">s</span><span class="op">|</span> <span class="ident">s</span>.<span class="ident">len</span>());

<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">maybe_some_len</span>, <span class="prelude-val">Some</span>(<span class="number">13</span>));</pre>
</div><h4 id='method.map_or' class="method"><span id='map_or.v' class='invisible'><code>pub fn <a href='#method.map_or' class='fnname'>map_or</a>&lt;U, F&gt;(self, default: U, f: F) -&gt; U <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>(T) -&gt; U,&nbsp;</span></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#423-428' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Applies a function to the contained value (if any),
or returns the provided default (if not).</p>
<h1 id="examples-9" class="section-header"><a href="#examples-9">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="string">&quot;foo&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">map_or</span>(<span class="number">42</span>, <span class="op">|</span><span class="ident">v</span><span class="op">|</span> <span class="ident">v</span>.<span class="ident">len</span>()), <span class="number">3</span>);

<span class="kw">let</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="kw-2">&amp;</span><span class="ident">str</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">map_or</span>(<span class="number">42</span>, <span class="op">|</span><span class="ident">v</span><span class="op">|</span> <span class="ident">v</span>.<span class="ident">len</span>()), <span class="number">42</span>);</pre>
</div><h4 id='method.map_or_else' class="method"><span id='map_or_else.v' class='invisible'><code>pub fn <a href='#method.map_or_else' class='fnname'>map_or_else</a>&lt;U, D, F&gt;(self, default: D, f: F) -&gt; U <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;D: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>() -&gt; U,<br>&nbsp;&nbsp;&nbsp;&nbsp;F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>(T) -&gt; U,&nbsp;</span></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#446-451' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Applies a function to the contained value (if any),
or computes a default (if not).</p>
<h1 id="examples-10" class="section-header"><a href="#examples-10">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">k</span> <span class="op">=</span> <span class="number">21</span>;

<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="string">&quot;foo&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">map_or_else</span>(<span class="op">||</span> <span class="number">2</span> <span class="op">*</span> <span class="ident">k</span>, <span class="op">|</span><span class="ident">v</span><span class="op">|</span> <span class="ident">v</span>.<span class="ident">len</span>()), <span class="number">3</span>);

<span class="kw">let</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="kw-2">&amp;</span><span class="ident">str</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">map_or_else</span>(<span class="op">||</span> <span class="number">2</span> <span class="op">*</span> <span class="ident">k</span>, <span class="op">|</span><span class="ident">v</span><span class="op">|</span> <span class="ident">v</span>.<span class="ident">len</span>()), <span class="number">42</span>);</pre>
</div><h4 id='method.ok_or' class="method"><span id='ok_or.v' class='invisible'><code>pub fn <a href='#method.ok_or' class='fnname'>ok_or</a>&lt;E&gt;(self, err: E) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;T, E&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#478-483' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Transforms the <code>Option&lt;T&gt;</code> into a <a href="../../std/result/enum.Result.html"><code>Result&lt;T, E&gt;</code></a>, mapping <a href="#variant.Some"><code>Some(v)</code></a> to
<a href="../../std/result/enum.Result.html#variant.Ok"><code>Ok(v)</code></a> and <a href="#variant.None"><code>None</code></a> to <a href="../../std/result/enum.Result.html#variant.Err"><code>Err(err)</code></a>.</p>
<p>Arguments passed to <code>ok_or</code> are eagerly evaluated; if you are passing the
result of a function call, it is recommended to use <a href="#method.ok_or_else"><code>ok_or_else</code></a>, which is
lazily evaluated.</p>
<h1 id="examples-11" class="section-header"><a href="#examples-11">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="string">&quot;foo&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">ok_or</span>(<span class="number">0</span>), <span class="prelude-val">Ok</span>(<span class="string">&quot;foo&quot;</span>));

<span class="kw">let</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="kw-2">&amp;</span><span class="ident">str</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">ok_or</span>(<span class="number">0</span>), <span class="prelude-val">Err</span>(<span class="number">0</span>));</pre>
</div><h4 id='method.ok_or_else' class="method"><span id='ok_or_else.v' class='invisible'><code>pub fn <a href='#method.ok_or_else' class='fnname'>ok_or_else</a>&lt;E, F&gt;(self, err: F) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;T, E&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>() -&gt; E,&nbsp;</span></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#505-510' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Transforms the <code>Option&lt;T&gt;</code> into a <a href="../../std/result/enum.Result.html"><code>Result&lt;T, E&gt;</code></a>, mapping <a href="#variant.Some"><code>Some(v)</code></a> to
<a href="../../std/result/enum.Result.html#variant.Ok"><code>Ok(v)</code></a> and <a href="#variant.None"><code>None</code></a> to <a href="../../std/result/enum.Result.html#variant.Err"><code>Err(err())</code></a>.</p>
<h1 id="examples-12" class="section-header"><a href="#examples-12">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="string">&quot;foo&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">ok_or_else</span>(<span class="op">||</span> <span class="number">0</span>), <span class="prelude-val">Ok</span>(<span class="string">&quot;foo&quot;</span>));

<span class="kw">let</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="kw-2">&amp;</span><span class="ident">str</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">ok_or_else</span>(<span class="op">||</span> <span class="number">0</span>), <span class="prelude-val">Err</span>(<span class="number">0</span>));</pre>
</div><h4 id='method.iter' class="method"><div class="important-traits"><div class='tooltip'>ⓘ<span class='tooltiptext'>Important traits for <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.Iter.html" title="struct core::option::Iter">Iter</a>&lt;'a, A&gt;</span></div><div class="content hidden"><h3 class="important">Important traits for <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.Iter.html" title="struct core::option::Iter">Iter</a>&lt;'a, A&gt;</h3><code class="content"><span class="where fmt-newline">impl&lt;'a, A&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html" title="trait core::iter::iterator::Iterator">Iterator</a> for <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.Iter.html" title="struct core::option::Iter">Iter</a>&lt;'a, A&gt;</span><span class="where fmt-newline">    type <a href='https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html#associatedtype.Item' class="type">Item</a> = <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a </a>A;</span></code></div></div><span id='iter.v' class='invisible'><code>pub fn <a href='#method.iter' class='fnname'>iter</a>(&amp;self) -&gt; <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.Iter.html" title="struct core::option::Iter">Iter</a>&lt;T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#529-531' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Returns an iterator over the possibly contained value.</p>
<h1 id="examples-13" class="section-header"><a href="#examples-13">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="number">4</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">iter</span>().<span class="ident">next</span>(), <span class="prelude-val">Some</span>(<span class="kw-2">&amp;</span><span class="number">4</span>));

<span class="kw">let</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">u32</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">iter</span>().<span class="ident">next</span>(), <span class="prelude-val">None</span>);</pre>
</div><h4 id='method.iter_mut' class="method"><div class="important-traits"><div class='tooltip'>ⓘ<span class='tooltiptext'>Important traits for <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.IterMut.html" title="struct core::option::IterMut">IterMut</a>&lt;'a, A&gt;</span></div><div class="content hidden"><h3 class="important">Important traits for <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.IterMut.html" title="struct core::option::IterMut">IterMut</a>&lt;'a, A&gt;</h3><code class="content"><span class="where fmt-newline">impl&lt;'a, A&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html" title="trait core::iter::iterator::Iterator">Iterator</a> for <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.IterMut.html" title="struct core::option::IterMut">IterMut</a>&lt;'a, A&gt;</span><span class="where fmt-newline">    type <a href='https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html#associatedtype.Item' class="type">Item</a> = <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a mut </a>A;</span></code></div></div><span id='iter_mut.v' class='invisible'><code>pub fn <a href='#method.iter_mut' class='fnname'>iter_mut</a>(&amp;mut self) -&gt; <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.IterMut.html" title="struct core::option::IterMut">IterMut</a>&lt;T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#550-552' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Returns a mutable iterator over the possibly contained value.</p>
<h1 id="examples-14" class="section-header"><a href="#examples-14">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="number">4</span>);
<span class="kw">match</span> <span class="ident">x</span>.<span class="ident">iter_mut</span>().<span class="ident">next</span>() {
    <span class="prelude-val">Some</span>(<span class="ident">v</span>) <span class="op">=&gt;</span> <span class="kw-2">*</span><span class="ident">v</span> <span class="op">=</span> <span class="number">42</span>,
    <span class="prelude-val">None</span> <span class="op">=&gt;</span> {},
}
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>, <span class="prelude-val">Some</span>(<span class="number">42</span>));

<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">u32</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">iter_mut</span>().<span class="ident">next</span>(), <span class="prelude-val">None</span>);</pre>
</div><h4 id='method.and' class="method"><span id='and.v' class='invisible'><code>pub fn <a href='#method.and' class='fnname'>and</a>&lt;U&gt;(self, optb: <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;U&gt;) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;U&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#583-588' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Returns <a href="#variant.None"><code>None</code></a> if the option is <a href="#variant.None"><code>None</code></a>, otherwise returns <code>optb</code>.</p>
<h1 id="examples-15" class="section-header"><a href="#examples-15">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="number">2</span>);
<span class="kw">let</span> <span class="ident">y</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="kw-2">&amp;</span><span class="ident">str</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">and</span>(<span class="ident">y</span>), <span class="prelude-val">None</span>);

<span class="kw">let</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">u32</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="kw">let</span> <span class="ident">y</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="string">&quot;foo&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">and</span>(<span class="ident">y</span>), <span class="prelude-val">None</span>);

<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="number">2</span>);
<span class="kw">let</span> <span class="ident">y</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="string">&quot;foo&quot;</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">and</span>(<span class="ident">y</span>), <span class="prelude-val">Some</span>(<span class="string">&quot;foo&quot;</span>));

<span class="kw">let</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">u32</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="kw">let</span> <span class="ident">y</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="kw-2">&amp;</span><span class="ident">str</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">and</span>(<span class="ident">y</span>), <span class="prelude-val">None</span>);</pre>
</div><h4 id='method.and_then' class="method"><span id='and_then.v' class='invisible'><code>pub fn <a href='#method.and_then' class='fnname'>and_then</a>&lt;U, F&gt;(self, f: F) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;U&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>(T) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;U&gt;,&nbsp;</span></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#610-615' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Returns <a href="#variant.None"><code>None</code></a> if the option is <a href="#variant.None"><code>None</code></a>, otherwise calls <code>f</code> with the
wrapped value and returns the result.</p>
<p>Some languages call this operation flatmap.</p>
<h1 id="examples-16" class="section-header"><a href="#examples-16">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">fn</span> <span class="ident">sq</span>(<span class="ident">x</span>: <span class="ident">u32</span>) <span class="op">-&gt;</span> <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">u32</span><span class="op">&gt;</span> { <span class="prelude-val">Some</span>(<span class="ident">x</span> <span class="op">*</span> <span class="ident">x</span>) }
<span class="kw">fn</span> <span class="ident">nope</span>(_: <span class="ident">u32</span>) <span class="op">-&gt;</span> <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">u32</span><span class="op">&gt;</span> { <span class="prelude-val">None</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">and_then</span>(<span class="ident">sq</span>).<span class="ident">and_then</span>(<span class="ident">sq</span>), <span class="prelude-val">Some</span>(<span class="number">16</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">and_then</span>(<span class="ident">sq</span>).<span class="ident">and_then</span>(<span class="ident">nope</span>), <span class="prelude-val">None</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">and_then</span>(<span class="ident">nope</span>).<span class="ident">and_then</span>(<span class="ident">sq</span>), <span class="prelude-val">None</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">None</span>.<span class="ident">and_then</span>(<span class="ident">sq</span>).<span class="ident">and_then</span>(<span class="ident">sq</span>), <span class="prelude-val">None</span>);</pre>
</div><h4 id='method.filter' class="method"><span id='filter.v' class='invisible'><code>pub fn <a href='#method.filter' class='fnname'>filter</a>&lt;P&gt;(self, predicate: P) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;P: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>(<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;</a>T) -&gt; <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a>,&nbsp;</span></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#643-650' 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>option_filter</code>)</div></div><div class='docblock'><p>Returns <code>None</code> if the option is <code>None</code>, otherwise calls <code>predicate</code>
with the wrapped value and returns:</p>
<ul>
<li><code>Some(t)</code> if <code>predicate</code> returns <code>true</code> (where <code>t</code> is the wrapped
value), and</li>
<li><code>None</code> if <code>predicate</code> returns <code>false</code>.</li>
</ul>
<p>This function works similar to <code>Iterator::filter()</code>. You can imagine
the <code>Option&lt;T&gt;</code> being an iterator over one or zero elements. <code>filter()</code>
lets you decide which elements to keep.</p>
<h1 id="examples-17" class="section-header"><a href="#examples-17">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="attribute">#![<span class="ident">feature</span>(<span class="ident">option_filter</span>)]</span>

<span class="kw">fn</span> <span class="ident">is_even</span>(<span class="ident">n</span>: <span class="kw-2">&amp;</span><span class="ident">i32</span>) <span class="op">-&gt;</span> <span class="ident">bool</span> {
    <span class="ident">n</span> <span class="op">%</span> <span class="number">2</span> <span class="op">==</span> <span class="number">0</span>
}

<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">None</span>.<span class="ident">filter</span>(<span class="ident">is_even</span>), <span class="prelude-val">None</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">filter</span>(<span class="ident">is_even</span>), <span class="prelude-val">None</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">Some</span>(<span class="number">4</span>).<span class="ident">filter</span>(<span class="ident">is_even</span>), <span class="prelude-val">Some</span>(<span class="number">4</span>));</pre>
</div><h4 id='method.or' class="method"><span id='or.v' class='invisible'><code>pub fn <a href='#method.or' class='fnname'>or</a>(self, optb: <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#681-686' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Returns the option if it contains a value, otherwise returns <code>optb</code>.</p>
<p>Arguments passed to <code>or</code> are eagerly evaluated; if you are passing the
result of a function call, it is recommended to use <a href="#method.or_else"><code>or_else</code></a>, which is
lazily evaluated.</p>
<h1 id="examples-18" class="section-header"><a href="#examples-18">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="number">2</span>);
<span class="kw">let</span> <span class="ident">y</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">or</span>(<span class="ident">y</span>), <span class="prelude-val">Some</span>(<span class="number">2</span>));

<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="kw">let</span> <span class="ident">y</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="number">100</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">or</span>(<span class="ident">y</span>), <span class="prelude-val">Some</span>(<span class="number">100</span>));

<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="number">2</span>);
<span class="kw">let</span> <span class="ident">y</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="number">100</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">or</span>(<span class="ident">y</span>), <span class="prelude-val">Some</span>(<span class="number">2</span>));

<span class="kw">let</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">u32</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="kw">let</span> <span class="ident">y</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>.<span class="ident">or</span>(<span class="ident">y</span>), <span class="prelude-val">None</span>);</pre>
</div><h4 id='method.or_else' class="method"><span id='or_else.v' class='invisible'><code>pub fn <a href='#method.or_else' class='fnname'>or_else</a>&lt;F&gt;(self, f: F) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>() -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;,&nbsp;</span></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#703-708' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Returns the option if it contains a value, otherwise calls <code>f</code> and
returns the result.</p>
<h1 id="examples-19" class="section-header"><a href="#examples-19">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">fn</span> <span class="ident">nobody</span>() <span class="op">-&gt;</span> <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="kw-2">&amp;</span><span class="lifetime">&#39;static</span> <span class="ident">str</span><span class="op">&gt;</span> { <span class="prelude-val">None</span> }
<span class="kw">fn</span> <span class="ident">vikings</span>() <span class="op">-&gt;</span> <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="kw-2">&amp;</span><span class="lifetime">&#39;static</span> <span class="ident">str</span><span class="op">&gt;</span> { <span class="prelude-val">Some</span>(<span class="string">&quot;vikings&quot;</span>) }

<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">Some</span>(<span class="string">&quot;barbarians&quot;</span>).<span class="ident">or_else</span>(<span class="ident">vikings</span>), <span class="prelude-val">Some</span>(<span class="string">&quot;barbarians&quot;</span>));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">None</span>.<span class="ident">or_else</span>(<span class="ident">vikings</span>), <span class="prelude-val">Some</span>(<span class="string">&quot;vikings&quot;</span>));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="prelude-val">None</span>.<span class="ident">or_else</span>(<span class="ident">nobody</span>), <span class="prelude-val">None</span>);</pre>
</div><h4 id='method.get_or_insert' class="method"><div class="important-traits"><div class='tooltip'>ⓘ<span class='tooltiptext'>Important traits for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a mut </a>R</span></div><div class="content hidden"><h3 class="important">Important traits for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a mut </a>R</h3><code class="content"><span class="where fmt-newline">impl&lt;'a, R&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/std/io/trait.Read.html" title="trait std::io::Read">Read</a> for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a mut </a>R <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;R: <a class="trait" href="https://doc.rust-lang.org/nightly/std/io/trait.Read.html" title="trait std::io::Read">Read</a> + ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,&nbsp;</span></span><span class="where fmt-newline">impl&lt;'a, W&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/std/io/trait.Write.html" title="trait std::io::Write">Write</a> for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a mut </a>W <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;W: <a class="trait" href="https://doc.rust-lang.org/nightly/std/io/trait.Write.html" title="trait std::io::Write">Write</a> + ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,&nbsp;</span></span><span class="where fmt-newline">impl&lt;'a, I&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html" title="trait core::iter::iterator::Iterator">Iterator</a> for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a mut </a>I <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;I: <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html" title="trait core::iter::iterator::Iterator">Iterator</a> + ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,&nbsp;</span></span><span class="where fmt-newline">    type <a href='https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html#associatedtype.Item' class="type">Item</a> = &lt;I as <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html" title="trait core::iter::iterator::Iterator">Iterator</a>&gt;::<a class="type" href="https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html#associatedtype.Item" title="type core::iter::iterator::Iterator::Item">Item</a>;</span></code></div></div><span id='get_or_insert.v' class='invisible'><code>pub fn <a href='#method.get_or_insert' class='fnname'>get_or_insert</a>(&amp;mut self, v: T) -&gt; <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;mut </a>T</code></span><span class='out-of-band'><div class='ghost'></div><div class='since' title='Stable since Rust version 1.20.0'>1.20.0</div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#735-745' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Inserts <code>v</code> into the option if it is <a href="#variant.None"><code>None</code></a>, then
returns a mutable reference to the contained value.</p>
<h1 id="examples-20" class="section-header"><a href="#examples-20">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">None</span>;

{
    <span class="kw">let</span> <span class="ident">y</span>: <span class="kw-2">&amp;</span><span class="kw-2">mut</span> <span class="ident">u32</span> <span class="op">=</span> <span class="ident">x</span>.<span class="ident">get_or_insert</span>(<span class="number">5</span>);
    <span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">y</span>, <span class="kw-2">&amp;</span><span class="number">5</span>);

    <span class="kw-2">*</span><span class="ident">y</span> <span class="op">=</span> <span class="number">7</span>;
}

<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>, <span class="prelude-val">Some</span>(<span class="number">7</span>));</pre>
</div><h4 id='method.get_or_insert_with' class="method"><div class="important-traits"><div class='tooltip'>ⓘ<span class='tooltiptext'>Important traits for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a mut </a>R</span></div><div class="content hidden"><h3 class="important">Important traits for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a mut </a>R</h3><code class="content"><span class="where fmt-newline">impl&lt;'a, R&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/std/io/trait.Read.html" title="trait std::io::Read">Read</a> for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a mut </a>R <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;R: <a class="trait" href="https://doc.rust-lang.org/nightly/std/io/trait.Read.html" title="trait std::io::Read">Read</a> + ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,&nbsp;</span></span><span class="where fmt-newline">impl&lt;'a, W&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/std/io/trait.Write.html" title="trait std::io::Write">Write</a> for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a mut </a>W <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;W: <a class="trait" href="https://doc.rust-lang.org/nightly/std/io/trait.Write.html" title="trait std::io::Write">Write</a> + ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,&nbsp;</span></span><span class="where fmt-newline">impl&lt;'a, I&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html" title="trait core::iter::iterator::Iterator">Iterator</a> for <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a mut </a>I <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;I: <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html" title="trait core::iter::iterator::Iterator">Iterator</a> + ?<a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sized.html" title="trait core::marker::Sized">Sized</a>,&nbsp;</span></span><span class="where fmt-newline">    type <a href='https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html#associatedtype.Item' class="type">Item</a> = &lt;I as <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html" title="trait core::iter::iterator::Iterator">Iterator</a>&gt;::<a class="type" href="https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html#associatedtype.Item" title="type core::iter::iterator::Iterator::Item">Item</a>;</span></code></div></div><span id='get_or_insert_with.v' class='invisible'><code>pub fn <a href='#method.get_or_insert_with' class='fnname'>get_or_insert_with</a>&lt;F&gt;(&amp;mut self, f: F) -&gt; <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;mut </a>T <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;F: <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/function/trait.FnOnce.html" title="trait core::ops::function::FnOnce">FnOnce</a>() -&gt; T,&nbsp;</span></code></span><span class='out-of-band'><div class='ghost'></div><div class='since' title='Stable since Rust version 1.20.0'>1.20.0</div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#768-778' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Inserts a value computed from <code>f</code> into the option if it is <a href="#variant.None"><code>None</code></a>, then
returns a mutable reference to the contained value.</p>
<h1 id="examples-21" class="section-header"><a href="#examples-21">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">None</span>;

{
    <span class="kw">let</span> <span class="ident">y</span>: <span class="kw-2">&amp;</span><span class="kw-2">mut</span> <span class="ident">u32</span> <span class="op">=</span> <span class="ident">x</span>.<span class="ident">get_or_insert_with</span>(<span class="op">||</span> <span class="number">5</span>);
    <span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">y</span>, <span class="kw-2">&amp;</span><span class="number">5</span>);

    <span class="kw-2">*</span><span class="ident">y</span> <span class="op">=</span> <span class="number">7</span>;
}

<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>, <span class="prelude-val">Some</span>(<span class="number">7</span>));</pre>
</div><h4 id='method.take' class="method"><span id='take.v' class='invisible'><code>pub fn <a href='#method.take' class='fnname'>take</a>(&amp;mut self) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#801-803' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Takes the value out of the option, leaving a <a href="#variant.None"><code>None</code></a> in its place.</p>
<h1 id="examples-22" class="section-header"><a href="#examples-22">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="number">2</span>);
<span class="ident">x</span>.<span class="ident">take</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>, <span class="prelude-val">None</span>);

<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">x</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">u32</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="ident">x</span>.<span class="ident">take</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>, <span class="prelude-val">None</span>);</pre>
</div></div><h3 id='impl-1' class='impl'><span class='in-band'><code>impl&lt;'a, T&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a </a>T&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a>,&nbsp;</span></code><a href='#impl-1' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#806-823' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.cloned' class="method"><span id='cloned.v' class='invisible'><code>pub fn <a href='#method.cloned' class='fnname'>cloned</a>(self) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#820-822' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Maps an <code>Option&lt;&amp;T&gt;</code> to an <code>Option&lt;T&gt;</code> by cloning the contents of the
option.</p>
<h1 id="examples-23" class="section-header"><a href="#examples-23">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="number">12</span>;
<span class="kw">let</span> <span class="ident">opt_x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="kw-2">&amp;</span><span class="ident">x</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">opt_x</span>, <span class="prelude-val">Some</span>(<span class="kw-2">&amp;</span><span class="number">12</span>));
<span class="kw">let</span> <span class="ident">cloned</span> <span class="op">=</span> <span class="ident">opt_x</span>.<span class="ident">cloned</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">cloned</span>, <span class="prelude-val">Some</span>(<span class="number">12</span>));</pre>
</div></div><h3 id='impl-2' class='impl'><span class='in-band'><code>impl&lt;'a, T&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a mut </a>T&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a>,&nbsp;</span></code><a href='#impl-2' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#825-843' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.cloned-1' class="method"><span id='cloned.v-1' class='invisible'><code>pub fn <a href='#method.cloned-1' class='fnname'>cloned</a>(self) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#840-842' 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>option_ref_mut_cloned</code>)</div></div><div class='docblock'><p>Maps an <code>Option&lt;&amp;mut T&gt;</code> to an <code>Option&lt;T&gt;</code> by cloning the contents of the
option.</p>
<h1 id="examples-24" class="section-header"><a href="#examples-24">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="attribute">#![<span class="ident">feature</span>(<span class="ident">option_ref_mut_cloned</span>)]</span>
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">x</span> <span class="op">=</span> <span class="number">12</span>;
<span class="kw">let</span> <span class="ident">opt_x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="kw-2">&amp;</span><span class="kw-2">mut</span> <span class="ident">x</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">opt_x</span>, <span class="prelude-val">Some</span>(<span class="kw-2">&amp;</span><span class="kw-2">mut</span> <span class="number">12</span>));
<span class="kw">let</span> <span class="ident">cloned</span> <span class="op">=</span> <span class="ident">opt_x</span>.<span class="ident">cloned</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">cloned</span>, <span class="prelude-val">Some</span>(<span class="number">12</span>));</pre>
</div></div><h3 id='impl-3' class='impl'><span class='in-band'><code>impl&lt;T&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/default/trait.Default.html" title="trait core::default::Default">Default</a>,&nbsp;</span></code><a href='#impl-3' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#845-882' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.unwrap_or_default' class="method"><span id='unwrap_or_default.v' class='invisible'><code>pub fn <a href='#method.unwrap_or_default' class='fnname'>unwrap_or_default</a>(self) -&gt; T</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#876-881' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Returns the contained value or a default</p>
<p>Consumes the <code>self</code> argument then, if <a href="#variant.Some"><code>Some</code></a>, returns the contained
value, otherwise if <a href="#variant.None"><code>None</code></a>, returns the <a href="../default/trait.Default.html#tymethod.default">default value</a> for that
type.</p>
<h1 id="examples-25" class="section-header"><a href="#examples-25">Examples</a></h1>
<p>Convert a string to an integer, turning poorly-formed strings
into 0 (the default value for integers). <a href="../../std/primitive.str.html#method.parse"><code>parse</code></a> converts
a string to any other type that implements <a href="../../std/str/trait.FromStr.html"><code>FromStr</code></a>, returning
<a href="#variant.None"><code>None</code></a> on error.</p>

<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">good_year_from_input</span> <span class="op">=</span> <span class="string">&quot;1909&quot;</span>;
<span class="kw">let</span> <span class="ident">bad_year_from_input</span> <span class="op">=</span> <span class="string">&quot;190blarg&quot;</span>;
<span class="kw">let</span> <span class="ident">good_year</span> <span class="op">=</span> <span class="ident">good_year_from_input</span>.<span class="ident">parse</span>().<span class="ident">ok</span>().<span class="ident">unwrap_or_default</span>();
<span class="kw">let</span> <span class="ident">bad_year</span> <span class="op">=</span> <span class="ident">bad_year_from_input</span>.<span class="ident">parse</span>().<span class="ident">ok</span>().<span class="ident">unwrap_or_default</span>();

<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="number">1909</span>, <span class="ident">good_year</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="number">0</span>, <span class="ident">bad_year</span>);</pre>
</div></div><h3 id='impl-4' class='impl'><span class='in-band'><code>impl&lt;T, E&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;<a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;T, E&gt;&gt;</code><a href='#impl-4' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#884-911' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.transpose' class="method"><span id='transpose.v' class='invisible'><code>pub fn <a href='#method.transpose' class='fnname'>transpose</a>(self) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;<a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;, E&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#904-910' 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>transpose_result</code>)</div></div><div class='docblock'><p>Transposes an <code>Option</code> of a <code>Result</code> into a <code>Result</code> of an <code>Option</code>.</p>
<p><code>None</code> will be mapped to <code>Ok(None)</code>.
<code>Some(Ok(_))</code> and <code>Some(Err(_))</code> will be mapped to <code>Ok(Some(_))</code> and <code>Err(_)</code>.</p>
<h1 id="examples-26" class="section-header"><a href="#examples-26">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="attribute">#![<span class="ident">feature</span>(<span class="ident">transpose_result</span>)]</span>

<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>, <span class="ident">Eq</span>, <span class="ident">PartialEq</span>)]</span>
<span class="kw">struct</span> <span class="ident">SomeErr</span>;

<span class="kw">let</span> <span class="ident">x</span>: <span class="prelude-ty">Result</span><span class="op">&lt;</span><span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">i32</span><span class="op">&gt;</span>, <span class="ident">SomeErr</span><span class="op">&gt;</span> <span class="op">=</span> <span class="prelude-val">Ok</span>(<span class="prelude-val">Some</span>(<span class="number">5</span>));
<span class="kw">let</span> <span class="ident">y</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="prelude-ty">Result</span><span class="op">&lt;</span><span class="ident">i32</span>, <span class="ident">SomeErr</span><span class="op">&gt;&gt;</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="prelude-val">Ok</span>(<span class="number">5</span>));
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">x</span>, <span class="ident">y</span>.<span class="ident">transpose</span>());</pre>
</div></div>
            <h2 id='implementations' class='small-section-header'>
              Trait Implementations<a href='#implementations' class='anchor'></a>
            </h2>
        <h3 id='impl-Debug' class='impl'><span class='in-band'><code>impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/fmt/trait.Debug.html" title="trait core::fmt::Debug">Debug</a> for <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/fmt/trait.Debug.html" title="trait core::fmt::Debug">Debug</a>,&nbsp;</span></code><a href='#impl-Debug' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' 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='https://doc.rust-lang.org/nightly/core/fmt/trait.Debug.html#tymethod.fmt' class='fnname'>fmt</a>(&amp;self, __arg_0: &amp;mut <a class="struct" href="https://doc.rust-lang.org/nightly/core/fmt/struct.Formatter.html" title="struct core::fmt::Formatter">Formatter</a>) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.unit.html">()</a>, <a class="struct" href="https://doc.rust-lang.org/nightly/core/fmt/struct.Error.html" title="struct core::fmt::Error">Error</a>&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Formats the value using the given formatter. <a href="https://doc.rust-lang.org/nightly/core/fmt/trait.Debug.html#tymethod.fmt">Read more</a></p>
</div></div><h3 id='impl-IntoIterator' class='impl'><span class='in-band'><code>impl&lt;'a, T&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html" title="trait core::iter::traits::IntoIterator">IntoIterator</a> for &amp;'a <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code><a href='#impl-IntoIterator' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><div class='since' title='Stable since Rust version 1.4.0'>1.4.0</div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#959-966' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='associatedtype.Item' class="type"><span id='Item.t' class='invisible'><code>type <a href='https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html#associatedtype.Item' class="type">Item</a> = <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a </a>T</code></span></h4>
<div class='docblock'><p>The type of the elements being iterated over.</p>
</div><h4 id='associatedtype.IntoIter' class="type"><span id='IntoIter.t' class='invisible'><code>type <a href='https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html#associatedtype.IntoIter' class="type">IntoIter</a> = <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.Iter.html" title="struct core::option::Iter">Iter</a>&lt;'a, T&gt;</code></span></h4>
<div class='docblock'><p>Which kind of iterator are we turning this into?</p>
</div><h4 id='method.into_iter' class="method"><div class="important-traits"><div class='tooltip'>ⓘ<span class='tooltiptext'>Important traits for <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.Iter.html" title="struct core::option::Iter">Iter</a>&lt;'a, A&gt;</span></div><div class="content hidden"><h3 class="important">Important traits for <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.Iter.html" title="struct core::option::Iter">Iter</a>&lt;'a, A&gt;</h3><code class="content"><span class="where fmt-newline">impl&lt;'a, A&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html" title="trait core::iter::iterator::Iterator">Iterator</a> for <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.Iter.html" title="struct core::option::Iter">Iter</a>&lt;'a, A&gt;</span><span class="where fmt-newline">    type <a href='https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html#associatedtype.Item' class="type">Item</a> = <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a </a>A;</span></code></div></div><span id='into_iter.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html#tymethod.into_iter' class='fnname'>into_iter</a>(self) -&gt; <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.Iter.html" title="struct core::option::Iter">Iter</a>&lt;'a, T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#963-965' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Creates an iterator from a value. <a href="https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html#tymethod.into_iter">Read more</a></p>
</div></div><h3 id='impl-IntoIterator-1' class='impl'><span class='in-band'><code>impl&lt;'a, T&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html" title="trait core::iter::traits::IntoIterator">IntoIterator</a> for &amp;'a mut <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code><a href='#impl-IntoIterator-1' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><div class='since' title='Stable since Rust version 1.4.0'>1.4.0</div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#969-976' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='associatedtype.Item-1' class="type"><span id='Item.t-1' class='invisible'><code>type <a href='https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html#associatedtype.Item' class="type">Item</a> = <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a mut </a>T</code></span></h4>
<div class='docblock'><p>The type of the elements being iterated over.</p>
</div><h4 id='associatedtype.IntoIter-1' class="type"><span id='IntoIter.t-1' class='invisible'><code>type <a href='https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html#associatedtype.IntoIter' class="type">IntoIter</a> = <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.IterMut.html" title="struct core::option::IterMut">IterMut</a>&lt;'a, T&gt;</code></span></h4>
<div class='docblock'><p>Which kind of iterator are we turning this into?</p>
</div><h4 id='method.into_iter-1' class="method"><div class="important-traits"><div class='tooltip'>ⓘ<span class='tooltiptext'>Important traits for <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.IterMut.html" title="struct core::option::IterMut">IterMut</a>&lt;'a, A&gt;</span></div><div class="content hidden"><h3 class="important">Important traits for <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.IterMut.html" title="struct core::option::IterMut">IterMut</a>&lt;'a, A&gt;</h3><code class="content"><span class="where fmt-newline">impl&lt;'a, A&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html" title="trait core::iter::iterator::Iterator">Iterator</a> for <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.IterMut.html" title="struct core::option::IterMut">IterMut</a>&lt;'a, A&gt;</span><span class="where fmt-newline">    type <a href='https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html#associatedtype.Item' class="type">Item</a> = <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;'a mut </a>A;</span></code></div></div><span id='into_iter.v-1' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html#tymethod.into_iter' class='fnname'>into_iter</a>(self) -&gt; <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.IterMut.html" title="struct core::option::IterMut">IterMut</a>&lt;'a, T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#973-975' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Creates an iterator from a value. <a href="https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html#tymethod.into_iter">Read more</a></p>
</div></div><h3 id='impl-IntoIterator-2' class='impl'><span class='in-band'><code>impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html" title="trait core::iter::traits::IntoIterator">IntoIterator</a> for <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code><a href='#impl-IntoIterator-2' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#935-956' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='associatedtype.Item-2' class="type"><span id='Item.t-2' class='invisible'><code>type <a href='https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html#associatedtype.Item' class="type">Item</a> = T</code></span></h4>
<div class='docblock'><p>The type of the elements being iterated over.</p>
</div><h4 id='associatedtype.IntoIter-2' class="type"><span id='IntoIter.t-2' class='invisible'><code>type <a href='https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html#associatedtype.IntoIter' class="type">IntoIter</a> = <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.IntoIter.html" title="struct core::option::IntoIter">IntoIter</a>&lt;T&gt;</code></span></h4>
<div class='docblock'><p>Which kind of iterator are we turning this into?</p>
</div><h4 id='method.into_iter-2' class="method"><div class="important-traits"><div class='tooltip'>ⓘ<span class='tooltiptext'>Important traits for <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.IntoIter.html" title="struct core::option::IntoIter">IntoIter</a>&lt;A&gt;</span></div><div class="content hidden"><h3 class="important">Important traits for <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.IntoIter.html" title="struct core::option::IntoIter">IntoIter</a>&lt;A&gt;</h3><code class="content"><span class="where fmt-newline">impl&lt;A&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html" title="trait core::iter::iterator::Iterator">Iterator</a> for <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.IntoIter.html" title="struct core::option::IntoIter">IntoIter</a>&lt;A&gt;</span><span class="where fmt-newline">    type <a href='https://doc.rust-lang.org/nightly/core/iter/iterator/trait.Iterator.html#associatedtype.Item' class="type">Item</a> = A;</span></code></div></div><span id='into_iter.v-2' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html#tymethod.into_iter' class='fnname'>into_iter</a>(self) -&gt; <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.IntoIter.html" title="struct core::option::IntoIter">IntoIter</a>&lt;T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#953-955' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Returns a consuming iterator over the possibly contained value.</p>
<h1 id="examples-27" class="section-header"><a href="#examples-27">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">Some</span>(<span class="string">&quot;string&quot;</span>);
<span class="kw">let</span> <span class="ident">v</span>: <span class="ident">Vec</span><span class="op">&lt;</span><span class="kw-2">&amp;</span><span class="ident">str</span><span class="op">&gt;</span> <span class="op">=</span> <span class="ident">x</span>.<span class="ident">into_iter</span>().<span class="ident">collect</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">v</span>, [<span class="string">&quot;string&quot;</span>]);

<span class="kw">let</span> <span class="ident">x</span> <span class="op">=</span> <span class="prelude-val">None</span>;
<span class="kw">let</span> <span class="ident">v</span>: <span class="ident">Vec</span><span class="op">&lt;</span><span class="kw-2">&amp;</span><span class="ident">str</span><span class="op">&gt;</span> <span class="op">=</span> <span class="ident">x</span>.<span class="ident">into_iter</span>().<span class="ident">collect</span>();
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">v</span>.<span class="ident">is_empty</span>());</pre>
</div></div><h3 id='impl-FromIterator%3COption%3CA%3E%3E' class='impl'><span class='in-band'><code>impl&lt;A, V&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/traits/trait.FromIterator.html" title="trait core::iter::traits::FromIterator">FromIterator</a>&lt;<a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;A&gt;&gt; for <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;V&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;V: <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/traits/trait.FromIterator.html" title="trait core::iter::traits::FromIterator">FromIterator</a>&lt;A&gt;,&nbsp;</span></code><a href='#impl-FromIterator%3COption%3CA%3E%3E' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#1147-1203' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.from_iter' class="method"><span id='from_iter.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/iter/traits/trait.FromIterator.html#tymethod.from_iter' class='fnname'>from_iter</a>&lt;I&gt;(iter: I) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;V&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;I: <a class="trait" href="https://doc.rust-lang.org/nightly/core/iter/traits/trait.IntoIterator.html" title="trait core::iter::traits::IntoIterator">IntoIterator</a>&lt;Item = <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;A&gt;&gt;,&nbsp;</span></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#1169-1202' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Takes each element in the <a href="../iter/trait.Iterator.html"><code>Iterator</code></a>: if it is <a href="enum.Option.html#variant.None"><code>None</code></a>, no further
elements are taken, and the <a href="enum.Option.html#variant.None"><code>None</code></a> is returned. Should no <a href="enum.Option.html#variant.None"><code>None</code></a> occur, a
container with the values of each <code>Option</code> is returned.</p>
<p>Here is an example which increments every integer in a vector,
checking for overflow:</p>

<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">u16</span>;

<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="kw">let</span> <span class="ident">res</span>: <span class="prelude-ty">Option</span><span class="op">&lt;</span><span class="ident">Vec</span><span class="op">&lt;</span><span class="ident">u16</span><span class="op">&gt;&gt;</span> <span class="op">=</span> <span class="ident">v</span>.<span class="ident">iter</span>().<span class="ident">map</span>(<span class="op">|</span><span class="kw-2">&amp;</span><span class="ident">x</span>: <span class="kw-2">&amp;</span><span class="ident">u16</span><span class="op">|</span>
    <span class="kw">if</span> <span class="ident">x</span> <span class="op">==</span> <span class="ident">u16</span>::<span class="ident">MAX</span> { <span class="prelude-val">None</span> }
    <span class="kw">else</span> { <span class="prelude-val">Some</span>(<span class="ident">x</span> <span class="op">+</span> <span class="number">1</span>) }
).<span class="ident">collect</span>();
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">res</span> <span class="op">==</span> <span class="prelude-val">Some</span>(<span class="macro">vec</span><span class="macro">!</span>[<span class="number">2</span>, <span class="number">3</span>]));</pre>
</div></div><h3 id='impl-Hash' class='impl'><span class='in-band'><code>impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/hash/trait.Hash.html" title="trait core::hash::Hash">Hash</a> for <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/hash/trait.Hash.html" title="trait core::hash::Hash">Hash</a>,&nbsp;</span></code><a href='#impl-Hash' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.hash' class="method"><span id='hash.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/hash/trait.Hash.html#tymethod.hash' class='fnname'>hash</a>&lt;__HT&gt;(&amp;self, __arg_0: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;mut </a>__HT) <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;__HT: <a class="trait" href="https://doc.rust-lang.org/nightly/core/hash/trait.Hasher.html" title="trait core::hash::Hasher">Hasher</a>,&nbsp;</span></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Feeds this value into the given [<code>Hasher</code>]. <a href="https://doc.rust-lang.org/nightly/core/hash/trait.Hash.html#tymethod.hash">Read more</a></p>
</div><h4 id='method.hash_slice' class="method"><span id='hash_slice.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/hash/trait.Hash.html#method.hash_slice' class='fnname'>hash_slice</a>&lt;H&gt;(data: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.slice.html">&amp;[Self]</a>, state: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;mut </a>H) <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;H: <a class="trait" href="https://doc.rust-lang.org/nightly/core/hash/trait.Hasher.html" title="trait core::hash::Hasher">Hasher</a>,&nbsp;</span></code></span><span class='out-of-band'><div class='ghost'></div><div class='since' title='Stable since Rust version 1.3.0'>1.3.0</div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/hash/mod.rs.html#202-208' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Feeds a slice of this type into the given [<code>Hasher</code>]. <a href="https://doc.rust-lang.org/nightly/core/hash/trait.Hash.html#method.hash_slice">Read more</a></p>
</div></div><h3 id='impl-Default' class='impl'><span class='in-band'><code>impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/default/trait.Default.html" title="trait core::default::Default">Default</a> for <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code><a href='#impl-Default' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#926-932' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.default' class="method"><span id='default.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/default/trait.Default.html#tymethod.default' class='fnname'>default</a>() -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#931' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Returns <a href="#variant.None"><code>None</code></a>.</p>
</div></div><h3 id='impl-Clone' class='impl'><span class='in-band'><code>impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a> for <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html" title="trait core::clone::Clone">Clone</a>,&nbsp;</span></code><a href='#impl-Clone' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.clone' class="method"><span id='clone.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html#tymethod.clone' class='fnname'>clone</a>(&amp;self) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Returns a copy of the value. <a href="https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html#tymethod.clone">Read more</a></p>
</div><h4 id='method.clone_from' class="method"><span id='clone_from.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html#method.clone_from' class='fnname'>clone_from</a>(&amp;mut self, source: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.reference.html">&amp;</a>Self)</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/clone.rs.html#112-114' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Performs copy-assignment from <code>source</code>. <a href="https://doc.rust-lang.org/nightly/core/clone/trait.Clone.html#method.clone_from">Read more</a></p>
</div></div><h3 id='impl-PartialOrd%3COption%3CT%3E%3E' class='impl'><span class='in-band'><code>impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/cmp/trait.PartialOrd.html" title="trait core::cmp::PartialOrd">PartialOrd</a>&lt;<a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;&gt; for <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/cmp/trait.PartialOrd.html" title="trait core::cmp::PartialOrd">PartialOrd</a>&lt;T&gt;,&nbsp;</span></code><a href='#impl-PartialOrd%3COption%3CT%3E%3E' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.partial_cmp' class="method"><span id='partial_cmp.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/cmp/trait.PartialOrd.html#tymethod.partial_cmp' class='fnname'>partial_cmp</a>(&amp;self, __arg_0: &amp;<a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;<a class="enum" href="https://doc.rust-lang.org/nightly/core/cmp/enum.Ordering.html" title="enum core::cmp::Ordering">Ordering</a>&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>This method returns an ordering between <code>self</code> and <code>other</code> values if one exists. <a href="https://doc.rust-lang.org/nightly/core/cmp/trait.PartialOrd.html#tymethod.partial_cmp">Read more</a></p>
</div><h4 id='method.lt' class="method"><span id='lt.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/cmp/trait.PartialOrd.html#method.lt' class='fnname'>lt</a>(&amp;self, __arg_0: &amp;<a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;) -&gt; <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>This method tests less than (for <code>self</code> and <code>other</code>) and is used by the <code>&lt;</code> operator. <a href="https://doc.rust-lang.org/nightly/core/cmp/trait.PartialOrd.html#method.lt">Read more</a></p>
</div><h4 id='method.le' class="method"><span id='le.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/cmp/trait.PartialOrd.html#method.le' class='fnname'>le</a>(&amp;self, __arg_0: &amp;<a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;) -&gt; <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>This method tests less than or equal to (for <code>self</code> and <code>other</code>) and is used by the <code>&lt;=</code> operator. <a href="https://doc.rust-lang.org/nightly/core/cmp/trait.PartialOrd.html#method.le">Read more</a></p>
</div><h4 id='method.gt' class="method"><span id='gt.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/cmp/trait.PartialOrd.html#method.gt' class='fnname'>gt</a>(&amp;self, __arg_0: &amp;<a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;) -&gt; <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>This method tests greater than (for <code>self</code> and <code>other</code>) and is used by the <code>&gt;</code> operator. <a href="https://doc.rust-lang.org/nightly/core/cmp/trait.PartialOrd.html#method.gt">Read more</a></p>
</div><h4 id='method.ge' class="method"><span id='ge.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/cmp/trait.PartialOrd.html#method.ge' class='fnname'>ge</a>(&amp;self, __arg_0: &amp;<a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;) -&gt; <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>This method tests greater than or equal to (for <code>self</code> and <code>other</code>) and is used by the <code>&gt;=</code> operator. <a href="https://doc.rust-lang.org/nightly/core/cmp/trait.PartialOrd.html#method.ge">Read more</a></p>
</div></div><h3 id='impl-Ord' class='impl'><span class='in-band'><code>impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/cmp/trait.Ord.html" title="trait core::cmp::Ord">Ord</a> for <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/cmp/trait.Ord.html" title="trait core::cmp::Ord">Ord</a>,&nbsp;</span></code><a href='#impl-Ord' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.cmp' class="method"><span id='cmp.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/cmp/trait.Ord.html#tymethod.cmp' class='fnname'>cmp</a>(&amp;self, __arg_0: &amp;<a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/cmp/enum.Ordering.html" title="enum core::cmp::Ordering">Ordering</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>This method returns an <code>Ordering</code> between <code>self</code> and <code>other</code>. <a href="https://doc.rust-lang.org/nightly/core/cmp/trait.Ord.html#tymethod.cmp">Read more</a></p>
</div><h4 id='method.max' class="method"><span id='max.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/cmp/trait.Ord.html#method.max' class='fnname'>max</a>(self, other: Self) -&gt; Self</code></span><span class='out-of-band'><div class='ghost'></div><div class='since' title='Stable since Rust version 1.21.0'>1.21.0</div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/cmp.rs.html#460-463' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Compares and returns the maximum of two values. <a href="https://doc.rust-lang.org/nightly/core/cmp/trait.Ord.html#method.max">Read more</a></p>
</div><h4 id='method.min' class="method"><span id='min.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/cmp/trait.Ord.html#method.min' class='fnname'>min</a>(self, other: Self) -&gt; Self</code></span><span class='out-of-band'><div class='ghost'></div><div class='since' title='Stable since Rust version 1.21.0'>1.21.0</div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/cmp.rs.html#476-479' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Compares and returns the minimum of two values. <a href="https://doc.rust-lang.org/nightly/core/cmp/trait.Ord.html#method.min">Read more</a></p>
</div></div><h3 id='impl-Eq' class='impl'><span class='in-band'><code>impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/cmp/trait.Eq.html" title="trait core::cmp::Eq">Eq</a> for <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/cmp/trait.Eq.html" title="trait core::cmp::Eq">Eq</a>,&nbsp;</span></code><a href='#impl-Eq' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'></div><h3 id='impl-PartialEq%3COption%3CT%3E%3E' class='impl'><span class='in-band'><code>impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/cmp/trait.PartialEq.html" title="trait core::cmp::PartialEq">PartialEq</a>&lt;<a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;&gt; for <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/cmp/trait.PartialEq.html" title="trait core::cmp::PartialEq">PartialEq</a>&lt;T&gt;,&nbsp;</span></code><a href='#impl-PartialEq%3COption%3CT%3E%3E' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.eq' class="method"><span id='eq.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/cmp/trait.PartialEq.html#tymethod.eq' class='fnname'>eq</a>(&amp;self, __arg_0: &amp;<a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;) -&gt; <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>This method tests for <code>self</code> and <code>other</code> values to be equal, and is used by <code>==</code>. <a href="https://doc.rust-lang.org/nightly/core/cmp/trait.PartialEq.html#tymethod.eq">Read more</a></p>
</div><h4 id='method.ne' class="method"><span id='ne.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/cmp/trait.PartialEq.html#method.ne' class='fnname'>ne</a>(&amp;self, __arg_0: &amp;<a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;) -&gt; <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.bool.html">bool</a></code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>This method tests for <code>!=</code>.</p>
</div></div><h3 id='impl-Try' class='impl'><span class='in-band'><code>impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/ops/try/trait.Try.html" title="trait core::ops::try::Try">Try</a> for <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code><a href='#impl-Try' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#1214-1229' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='associatedtype.Ok' class="type"><span id='Ok.t' class='invisible'><code>type <a href='https://doc.rust-lang.org/nightly/core/ops/try/trait.Try.html#associatedtype.Ok' class="type">Ok</a> = T</code></span></h4>
<div class='stability'><div class='stab unstable'><span class=microscope>🔬</span> This is a nightly-only experimental API.  (<code>try_trait</code>)</div></div><div class='docblock'><p>The type of this value when viewed as successful.</p>
</div><h4 id='associatedtype.Error' class="type"><span id='Error.t' class='invisible'><code>type <a href='https://doc.rust-lang.org/nightly/core/ops/try/trait.Try.html#associatedtype.Error' class="type">Error</a> = <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.NoneError.html" title="struct core::option::NoneError">NoneError</a></code></span></h4>
<div class='stability'><div class='stab unstable'><span class=microscope>🔬</span> This is a nightly-only experimental API.  (<code>try_trait</code>)</div></div><div class='docblock'><p>The type of this value when viewed as failed.</p>
</div><h4 id='method.into_result' class="method"><span id='into_result.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/ops/try/trait.Try.html#tymethod.into_result' class='fnname'>into_result</a>(self) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/result/enum.Result.html" title="enum core::result::Result">Result</a>&lt;T, <a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.NoneError.html" title="struct core::option::NoneError">NoneError</a>&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#1218-1220' 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>try_trait</code>)</div></div><div class='docblock'><p>Applies the &quot;?&quot; operator. A return of <code>Ok(t)</code> means that the execution should continue normally, and the result of <code>?</code> is the value <code>t</code>. A return of <code>Err(e)</code> means that execution should branch to the innermost enclosing <code>catch</code>, or return from the function. <a href="https://doc.rust-lang.org/nightly/core/ops/try/trait.Try.html#tymethod.into_result">Read more</a></p>
</div><h4 id='method.from_ok' class="method"><span id='from_ok.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/ops/try/trait.Try.html#tymethod.from_ok' class='fnname'>from_ok</a>(v: T) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#1222-1224' 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>try_trait</code>)</div></div><div class='docblock'><p>Wrap an OK value to construct the composite result. For example, <code>Result::Ok(x)</code> and <code>Result::from_ok(x)</code> are equivalent. <a href="https://doc.rust-lang.org/nightly/core/ops/try/trait.Try.html#tymethod.from_ok">Read more</a></p>
</div><h4 id='method.from_error' class="method"><span id='from_error.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/ops/try/trait.Try.html#tymethod.from_error' class='fnname'>from_error</a>(<a class="struct" href="https://doc.rust-lang.org/nightly/core/option/struct.NoneError.html" title="struct core::option::NoneError">NoneError</a>) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#1226-1228' 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>try_trait</code>)</div></div><div class='docblock'><p>Wrap an error value to construct the composite result. For example, <code>Result::Err(x)</code> and <code>Result::from_error(x)</code> are equivalent. <a href="https://doc.rust-lang.org/nightly/core/ops/try/trait.Try.html#tymethod.from_error">Read more</a></p>
</div></div><h3 id='impl-From%3CT%3E' class='impl'><span class='in-band'><code>impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html" title="trait core::convert::From">From</a>&lt;T&gt; for <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code><a href='#impl-From%3CT%3E' 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='https://doc.rust-lang.org/nightly/src/core/option.rs.html#979-983' title='goto source code'>[src]</a></span></h3>
<div class='impl-items'><h4 id='method.from' class="method"><span id='from.v' class='invisible'><code>fn <a href='https://doc.rust-lang.org/nightly/core/convert/trait.From.html#tymethod.from' class='fnname'>from</a>(val: T) -&gt; <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt;</code></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#980-982' title='goto source code'>[src]</a></span></h4>
<div class='docblock'><p>Performs the conversion.</p>
</div></div><h3 id='impl-Copy' class='impl'><span class='in-band'><code>impl&lt;T&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Copy.html" title="trait core::marker::Copy">Copy</a> for <a class="enum" href="../enum_primitive/enum.Option.html" title="enum enum_primitive::Option">Option</a>&lt;T&gt; <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;T: <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Copy.html" title="trait core::marker::Copy">Copy</a>,&nbsp;</span></code><a href='#impl-Copy' class='anchor'></a></span><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/core/option.rs.html#157' title='goto source code'>[src]</a></span></h3>
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