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<p class='location'>Struct Error</p><div class="sidebar-elems"><div class="block items"><a class="sidebar-title" href="#methods">Methods</a><div class="sidebar-links"><a href="#method.new">new</a><a href="#method.last_os_error">last_os_error</a><a href="#method.from_raw_os_error">from_raw_os_error</a><a href="#method.raw_os_error">raw_os_error</a><a href="#method.get_ref">get_ref</a><a href="#method.get_mut">get_mut</a><a href="#method.into_inner">into_inner</a><a href="#method.kind">kind</a></div><a class="sidebar-title" href="#implementations">Trait Implementations</a><div class="sidebar-links"><a href="#impl-Display">Display</a><a href="#impl-From%3CErrorKind%3E">From&lt;ErrorKind&gt;</a><a href="#impl-From%3CNulError%3E">From&lt;NulError&gt;</a><a href="#impl-From%3CIntoInnerError%3CW%3E%3E">From&lt;IntoInnerError&lt;W&gt;&gt;</a><a href="#impl-Error">Error</a><a href="#impl-Debug">Debug</a></div><a class="sidebar-title" href="#synthetic-implementations">Auto Trait Implementations</a><div class="sidebar-links"><a href="#impl-Send">Send</a><a href="#impl-Sync">Sync</a></div></div><p class='location'><a href='../index.html'>tokio</a>::<wbr><a href='index.html'>io</a></p><script>window.sidebarCurrent = {name: 'Error', ty: 'struct', relpath: ''};</script><script defer src="sidebar-items.js"></script></div>
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<section id='main' class="content"><h1 class='fqn'><span class='in-band'>Struct <a href='../index.html'>tokio</a>::<wbr><a href='index.html'>io</a>::<wbr><a class="struct" href=''>Error</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/std/io/error.rs.html#66-68' title='goto source code'>[src]</a></span></h1><div class="docblock type-decl"><pre class='rust struct'>pub struct Error { /* fields omitted */ }</pre></div><div class='docblock'><p>The error type for I/O operations of the <a href="../io/trait.Read.html"><code>Read</code></a>, <a href="../io/trait.Write.html"><code>Write</code></a>, <a href="../io/trait.Seek.html"><code>Seek</code></a>, and
associated traits.</p>
<p>Errors mostly originate from the underlying OS, but custom instances of
<code>Error</code> can be created with crafted error messages and a particular value of
<a href="enum.ErrorKind.html"><code>ErrorKind</code></a>.</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'><table class='table-display'><tbody><tr><td><code>impl <a class="struct" href="../../tokio/io/struct.Error.html" title="struct tokio::io::Error">Error</a></code><a href='#impl' class='anchor'></a></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/error.rs.html#232-515' title='goto source code'>[src]</a></span></td></tr></tbody></table></h3><div class='impl-items'><h4 id='method.new' class="method"><span id='new.v' class='invisible'><table class='table-display'><tbody><tr><td><code>pub fn <a href='#method.new' class='fnname'>new</a>&lt;E&gt;(kind: <a class="enum" href="../../tokio/io/enum.ErrorKind.html" title="enum tokio::io::ErrorKind">ErrorKind</a>, error: E) -&gt; <a class="struct" href="../../tokio/io/struct.Error.html" title="struct tokio::io::Error">Error</a> <span class="where fmt-newline">where<br>&nbsp;&nbsp;&nbsp;&nbsp;E: <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.Into.html" title="trait core::convert::Into">Into</a>&lt;<a class="struct" href="https://doc.rust-lang.org/nightly/alloc/boxed/struct.Box.html" title="struct alloc::boxed::Box">Box</a>&lt;<a class="trait" href="https://doc.rust-lang.org/nightly/std/error/trait.Error.html" title="trait std::error::Error">Error</a> + 'static + <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sync.html" title="trait core::marker::Sync">Sync</a> + <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a>&gt;&gt;,&nbsp;</span></code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/error.rs.html#252-256' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Creates a new I/O error from a known kind of error as well as an
arbitrary error payload.</p>
<p>This function is used to generically create I/O errors which do not
originate from the OS itself. The <code>error</code> argument is an arbitrary
payload which will be contained in this <code>Error</code>.</p>
<h1 id="examples" class="section-header"><a href="#examples">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">io</span>::{<span class="ident">Error</span>, <span class="ident">ErrorKind</span>};
<span class="comment">// errors can be created from strings</span>
<span class="kw">let</span> <span class="ident">custom_error</span> <span class="op">=</span> <span class="ident">Error</span>::<span class="ident">new</span>(<span class="ident">ErrorKind</span>::<span class="ident">Other</span>, <span class="string">&quot;oh no!&quot;</span>);
<span class="comment">// errors can also be created from other errors</span>
<span class="kw">let</span> <span class="ident">custom_error2</span> <span class="op">=</span> <span class="ident">Error</span>::<span class="ident">new</span>(<span class="ident">ErrorKind</span>::<span class="ident">Interrupted</span>, <span class="ident">custom_error</span>);</pre>
</div><h4 id='method.last_os_error' class="method"><span id='last_os_error.v' class='invisible'><table class='table-display'><tbody><tr><td><code>pub fn <a href='#method.last_os_error' class='fnname'>last_os_error</a>() -&gt; <a class="struct" href="../../tokio/io/struct.Error.html" title="struct tokio::io::Error">Error</a></code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/error.rs.html#281-283' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Returns an error representing the last OS error which occurred.</p>
<p>This function reads the value of <code>errno</code> for the target platform (e.g.
<code>GetLastError</code> on Windows) and will return a corresponding instance of
<code>Error</code> for the error code.</p>
<h1 id="examples-1" class="section-header"><a href="#examples-1">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">io</span>::<span class="ident">Error</span>;
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;last OS error: {:?}&quot;</span>, <span class="ident">Error</span>::<span class="ident">last_os_error</span>());</pre>
</div><h4 id='method.from_raw_os_error' class="method"><span id='from_raw_os_error.v' class='invisible'><table class='table-display'><tbody><tr><td><code>pub fn <a href='#method.from_raw_os_error' class='fnname'>from_raw_os_error</a>(code: <a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.i32.html">i32</a>) -&gt; <a class="struct" href="../../tokio/io/struct.Error.html" title="struct tokio::io::Error">Error</a></code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/error.rs.html#311-313' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Creates a new instance of an <code>Error</code> from a particular OS error code.</p>
<h1 id="examples-2" class="section-header"><a href="#examples-2">Examples</a></h1>
<p>On Linux:</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">io</span>;
<span class="kw">let</span> <span class="ident">error</span> <span class="op">=</span> <span class="ident">io</span>::<span class="ident">Error</span>::<span class="ident">from_raw_os_error</span>(<span class="number">22</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">error</span>.<span class="ident">kind</span>(), <span class="ident">io</span>::<span class="ident">ErrorKind</span>::<span class="ident">InvalidInput</span>);</pre>
<p>On Windows:</p>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">io</span>;
<span class="kw">let</span> <span class="ident">error</span> <span class="op">=</span> <span class="ident">io</span>::<span class="ident">Error</span>::<span class="ident">from_raw_os_error</span>(<span class="number">10022</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">error</span>.<span class="ident">kind</span>(), <span class="ident">io</span>::<span class="ident">ErrorKind</span>::<span class="ident">InvalidInput</span>);</pre>
</div><h4 id='method.raw_os_error' class="method"><span id='raw_os_error.v' class='invisible'><table class='table-display'><tbody><tr><td><code>pub fn <a href='#method.raw_os_error' class='fnname'>raw_os_error</a>(&amp;self) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.i32.html">i32</a>&gt;</code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/error.rs.html#342-348' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Returns the OS error that this error represents (if any).</p>
<p>If this <code>Error</code> was constructed via <code>last_os_error</code> or
<code>from_raw_os_error</code>, then this function will return <code>Some</code>, otherwise
it will return <code>None</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">use</span> <span class="ident">std</span>::<span class="ident">io</span>::{<span class="ident">Error</span>, <span class="ident">ErrorKind</span>};
<span class="kw">fn</span> <span class="ident">print_os_error</span>(<span class="ident">err</span>: <span class="kw-2">&amp;</span><span class="ident">Error</span>) {
<span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">raw_os_err</span>) <span class="op">=</span> <span class="ident">err</span>.<span class="ident">raw_os_error</span>() {
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;raw OS error: {:?}&quot;</span>, <span class="ident">raw_os_err</span>);
} <span class="kw">else</span> {
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;Not an OS error&quot;</span>);
}
}
<span class="kw">fn</span> <span class="ident">main</span>() {
<span class="comment">// Will print &quot;raw OS error: ...&quot;.</span>
<span class="ident">print_os_error</span>(<span class="kw-2">&amp;</span><span class="ident">Error</span>::<span class="ident">last_os_error</span>());
<span class="comment">// Will print &quot;Not an OS error&quot;.</span>
<span class="ident">print_os_error</span>(<span class="kw-2">&amp;</span><span class="ident">Error</span>::<span class="ident">new</span>(<span class="ident">ErrorKind</span>::<span class="ident">Other</span>, <span class="string">&quot;oh no!&quot;</span>));
}</pre>
</div><h4 id='method.get_ref' class="method"><span id='get_ref.v' class='invisible'><table class='table-display'><tbody><tr><td><code>pub fn <a href='#method.get_ref' class='fnname'>get_ref</a>(&amp;self) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;&amp;(<a class="trait" href="https://doc.rust-lang.org/nightly/std/error/trait.Error.html" title="trait std::error::Error">Error</a> + 'static + <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sync.html" title="trait core::marker::Sync">Sync</a> + <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a>)&gt;</code></span></td><td><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/std/io/error.rs.html#376-382' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Returns a reference to the inner error wrapped by this error (if any).</p>
<p>If this <code>Error</code> was constructed via <code>new</code> then this function will
return <code>Some</code>, otherwise it will return <code>None</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">use</span> <span class="ident">std</span>::<span class="ident">io</span>::{<span class="ident">Error</span>, <span class="ident">ErrorKind</span>};
<span class="kw">fn</span> <span class="ident">print_error</span>(<span class="ident">err</span>: <span class="kw-2">&amp;</span><span class="ident">Error</span>) {
<span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">inner_err</span>) <span class="op">=</span> <span class="ident">err</span>.<span class="ident">get_ref</span>() {
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;Inner error: {:?}&quot;</span>, <span class="ident">inner_err</span>);
} <span class="kw">else</span> {
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;No inner error&quot;</span>);
}
}
<span class="kw">fn</span> <span class="ident">main</span>() {
<span class="comment">// Will print &quot;No inner error&quot;.</span>
<span class="ident">print_error</span>(<span class="kw-2">&amp;</span><span class="ident">Error</span>::<span class="ident">last_os_error</span>());
<span class="comment">// Will print &quot;Inner error: ...&quot;.</span>
<span class="ident">print_error</span>(<span class="kw-2">&amp;</span><span class="ident">Error</span>::<span class="ident">new</span>(<span class="ident">ErrorKind</span>::<span class="ident">Other</span>, <span class="string">&quot;oh no!&quot;</span>));
}</pre>
</div><h4 id='method.get_mut' class="method"><span id='get_mut.v' class='invisible'><table class='table-display'><tbody><tr><td><code>pub fn <a href='#method.get_mut' class='fnname'>get_mut</a>(&amp;mut self) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;&amp;mut (<a class="trait" href="https://doc.rust-lang.org/nightly/std/error/trait.Error.html" title="trait std::error::Error">Error</a> + 'static + <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sync.html" title="trait core::marker::Sync">Sync</a> + <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a>)&gt;</code></span></td><td><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/std/io/error.rs.html#447-453' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Returns a mutable reference to the inner error wrapped by this error
(if any).</p>
<p>If this <code>Error</code> was constructed via <code>new</code> then this function will
return <code>Some</code>, otherwise it will return <code>None</code>.</p>
<h1 id="examples-5" class="section-header"><a href="#examples-5">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">io</span>::{<span class="ident">Error</span>, <span class="ident">ErrorKind</span>};
<span class="kw">use</span> <span class="ident">std</span>::{<span class="ident">error</span>, <span class="ident">fmt</span>};
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">fmt</span>::<span class="ident">Display</span>;
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>)]</span>
<span class="kw">struct</span> <span class="ident">MyError</span> {
<span class="ident">v</span>: <span class="ident">String</span>,
}
<span class="kw">impl</span> <span class="ident">MyError</span> {
<span class="kw">fn</span> <span class="ident">new</span>() <span class="op">-&gt;</span> <span class="ident">MyError</span> {
<span class="ident">MyError</span> {
<span class="ident">v</span>: <span class="string">&quot;oh no!&quot;</span>.<span class="ident">to_string</span>()
}
}
<span class="kw">fn</span> <span class="ident">change_message</span>(<span class="kw-2">&amp;</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">new_message</span>: <span class="kw-2">&amp;</span><span class="ident">str</span>) {
<span class="self">self</span>.<span class="ident">v</span> <span class="op">=</span> <span class="ident">new_message</span>.<span class="ident">to_string</span>();
}
}
<span class="kw">impl</span> <span class="ident">error</span>::<span class="ident">Error</span> <span class="kw">for</span> <span class="ident">MyError</span> {
<span class="kw">fn</span> <span class="ident">description</span>(<span class="kw-2">&amp;</span><span class="self">self</span>) <span class="op">-&gt;</span> <span class="kw-2">&amp;</span><span class="ident">str</span> { <span class="kw-2">&amp;</span><span class="self">self</span>.<span class="ident">v</span> }
}
<span class="kw">impl</span> <span class="ident">Display</span> <span class="kw">for</span> <span class="ident">MyError</span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&amp;</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&amp;</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-&gt;</span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
<span class="macro">write</span><span class="macro">!</span>(<span class="ident">f</span>, <span class="string">&quot;MyError: {}&quot;</span>, <span class="kw-2">&amp;</span><span class="self">self</span>.<span class="ident">v</span>)
}
}
<span class="kw">fn</span> <span class="ident">change_error</span>(<span class="kw-2">mut</span> <span class="ident">err</span>: <span class="ident">Error</span>) <span class="op">-&gt;</span> <span class="ident">Error</span> {
<span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">inner_err</span>) <span class="op">=</span> <span class="ident">err</span>.<span class="ident">get_mut</span>() {
<span class="ident">inner_err</span>.<span class="ident">downcast_mut</span>::<span class="op">&lt;</span><span class="ident">MyError</span><span class="op">&gt;</span>().<span class="ident">unwrap</span>().<span class="ident">change_message</span>(<span class="string">&quot;I&#39;ve been changed!&quot;</span>);
}
<span class="ident">err</span>
}
<span class="kw">fn</span> <span class="ident">print_error</span>(<span class="ident">err</span>: <span class="kw-2">&amp;</span><span class="ident">Error</span>) {
<span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">inner_err</span>) <span class="op">=</span> <span class="ident">err</span>.<span class="ident">get_ref</span>() {
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;Inner error: {}&quot;</span>, <span class="ident">inner_err</span>);
} <span class="kw">else</span> {
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;No inner error&quot;</span>);
}
}
<span class="kw">fn</span> <span class="ident">main</span>() {
<span class="comment">// Will print &quot;No inner error&quot;.</span>
<span class="ident">print_error</span>(<span class="kw-2">&amp;</span><span class="ident">change_error</span>(<span class="ident">Error</span>::<span class="ident">last_os_error</span>()));
<span class="comment">// Will print &quot;Inner error: ...&quot;.</span>
<span class="ident">print_error</span>(<span class="kw-2">&amp;</span><span class="ident">change_error</span>(<span class="ident">Error</span>::<span class="ident">new</span>(<span class="ident">ErrorKind</span>::<span class="ident">Other</span>, <span class="ident">MyError</span>::<span class="ident">new</span>())));
}</pre>
</div><h4 id='method.into_inner' class="method"><span id='into_inner.v' class='invisible'><table class='table-display'><tbody><tr><td><code>pub fn <a href='#method.into_inner' class='fnname'>into_inner</a>(self) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;<a class="struct" href="https://doc.rust-lang.org/nightly/alloc/boxed/struct.Box.html" title="struct alloc::boxed::Box">Box</a>&lt;<a class="trait" href="https://doc.rust-lang.org/nightly/std/error/trait.Error.html" title="trait std::error::Error">Error</a> + 'static + <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sync.html" title="trait core::marker::Sync">Sync</a> + <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a>&gt;&gt;</code></span></td><td><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/std/io/error.rs.html#481-487' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Consumes the <code>Error</code>, returning its inner error (if any).</p>
<p>If this <code>Error</code> was constructed via <code>new</code> then this function will
return <code>Some</code>, otherwise it will return <code>None</code>.</p>
<h1 id="examples-6" class="section-header"><a href="#examples-6">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">io</span>::{<span class="ident">Error</span>, <span class="ident">ErrorKind</span>};
<span class="kw">fn</span> <span class="ident">print_error</span>(<span class="ident">err</span>: <span class="ident">Error</span>) {
<span class="kw">if</span> <span class="kw">let</span> <span class="prelude-val">Some</span>(<span class="ident">inner_err</span>) <span class="op">=</span> <span class="ident">err</span>.<span class="ident">into_inner</span>() {
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;Inner error: {}&quot;</span>, <span class="ident">inner_err</span>);
} <span class="kw">else</span> {
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;No inner error&quot;</span>);
}
}
<span class="kw">fn</span> <span class="ident">main</span>() {
<span class="comment">// Will print &quot;No inner error&quot;.</span>
<span class="ident">print_error</span>(<span class="ident">Error</span>::<span class="ident">last_os_error</span>());
<span class="comment">// Will print &quot;Inner error: ...&quot;.</span>
<span class="ident">print_error</span>(<span class="ident">Error</span>::<span class="ident">new</span>(<span class="ident">ErrorKind</span>::<span class="ident">Other</span>, <span class="string">&quot;oh no!&quot;</span>));
}</pre>
</div><h4 id='method.kind' class="method"><span id='kind.v' class='invisible'><table class='table-display'><tbody><tr><td><code>pub fn <a href='#method.kind' class='fnname'>kind</a>(&amp;self) -&gt; <a class="enum" href="../../tokio/io/enum.ErrorKind.html" title="enum tokio::io::ErrorKind">ErrorKind</a></code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/error.rs.html#508-514' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Returns the corresponding <code>ErrorKind</code> for this error.</p>
<h1 id="examples-7" class="section-header"><a href="#examples-7">Examples</a></h1>
<pre class="rust rust-example-rendered">
<span class="kw">use</span> <span class="ident">std</span>::<span class="ident">io</span>::{<span class="ident">Error</span>, <span class="ident">ErrorKind</span>};
<span class="kw">fn</span> <span class="ident">print_error</span>(<span class="ident">err</span>: <span class="ident">Error</span>) {
<span class="macro">println</span><span class="macro">!</span>(<span class="string">&quot;{:?}&quot;</span>, <span class="ident">err</span>.<span class="ident">kind</span>());
}
<span class="kw">fn</span> <span class="ident">main</span>() {
<span class="comment">// Will print &quot;No inner error&quot;.</span>
<span class="ident">print_error</span>(<span class="ident">Error</span>::<span class="ident">last_os_error</span>());
<span class="comment">// Will print &quot;Inner error: ...&quot;.</span>
<span class="ident">print_error</span>(<span class="ident">Error</span>::<span class="ident">new</span>(<span class="ident">ErrorKind</span>::<span class="ident">AddrInUse</span>, <span class="string">&quot;oh no!&quot;</span>));
}</pre>
</div></div>
<h2 id='implementations' class='small-section-header'>
Trait Implementations<a href='#implementations' class='anchor'></a>
</h2>
<div id='implementations-list'>
<h3 id='impl-Display' class='impl'><span class='in-band'><table class='table-display'><tbody><tr><td><code>impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/fmt/trait.Display.html" title="trait core::fmt::Display">Display</a> for <a class="struct" href="../../tokio/io/struct.Error.html" title="struct tokio::io::Error">Error</a></code><a href='#impl-Display' class='anchor'></a></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/error.rs.html#532-543' title='goto source code'>[src]</a></span></td></tr></tbody></table></h3><div class='impl-items'><h4 id='method.fmt' class="method"><span id='fmt.v' class='invisible'><table class='table-display'><tbody><tr><td><code>fn <a href='https://doc.rust-lang.org/nightly/core/fmt/trait.Display.html#tymethod.fmt' class='fnname'>fmt</a>(&amp;self, fmt: &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></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/error.rs.html#533-542' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Formats the value using the given formatter. <a href="https://doc.rust-lang.org/nightly/core/fmt/trait.Display.html#tymethod.fmt">Read more</a></p>
</div></div><h3 id='impl-From%3CErrorKind%3E' class='impl'><span class='in-band'><table class='table-display'><tbody><tr><td><code>impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html" title="trait core::convert::From">From</a>&lt;<a class="enum" href="../../tokio/io/enum.ErrorKind.html" title="enum tokio::io::ErrorKind">ErrorKind</a>&gt; for <a class="struct" href="../../tokio/io/struct.Error.html" title="struct tokio::io::Error">Error</a></code><a href='#impl-From%3CErrorKind%3E' class='anchor'></a></span></td><td><span class='out-of-band'><div class='ghost'></div><div class='since' title='Stable since Rust version 1.14.0'>1.14.0</div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/error.rs.html#223-230' title='goto source code'>[src]</a></span></td></tr></tbody></table></h3><div class='docblock'><p>Intended for use for errors not exposed to the user, where allocating onto
the heap (for normal construction via Error::new) is too costly.</p>
</div><div class='impl-items'><h4 id='method.from' class="method"><span id='from.v' class='invisible'><table class='table-display'><tbody><tr><td><code>fn <a href='https://doc.rust-lang.org/nightly/core/convert/trait.From.html#tymethod.from' class='fnname'>from</a>(kind: <a class="enum" href="../../tokio/io/enum.ErrorKind.html" title="enum tokio::io::ErrorKind">ErrorKind</a>) -&gt; <a class="struct" href="../../tokio/io/struct.Error.html" title="struct tokio::io::Error">Error</a></code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/error.rs.html#225-229' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Performs the conversion.</p>
</div></div><h3 id='impl-From%3CNulError%3E' class='impl'><span class='in-band'><table class='table-display'><tbody><tr><td><code>impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html" title="trait core::convert::From">From</a>&lt;<a class="struct" href="https://doc.rust-lang.org/nightly/std/ffi/c_str/struct.NulError.html" title="struct std::ffi::c_str::NulError">NulError</a>&gt; for <a class="struct" href="../../tokio/io/struct.Error.html" title="struct tokio::io::Error">Error</a></code><a href='#impl-From%3CNulError%3E' class='anchor'></a></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/ffi/c_str.rs.html#801-806' title='goto source code'>[src]</a></span></td></tr></tbody></table></h3><div class='impl-items'><h4 id='method.from-1' class="method"><span id='from.v-1' class='invisible'><table class='table-display'><tbody><tr><td><code>fn <a href='https://doc.rust-lang.org/nightly/core/convert/trait.From.html#tymethod.from' class='fnname'>from</a>(<a class="struct" href="https://doc.rust-lang.org/nightly/std/ffi/c_str/struct.NulError.html" title="struct std::ffi::c_str::NulError">NulError</a>) -&gt; <a class="struct" href="../../tokio/io/struct.Error.html" title="struct tokio::io::Error">Error</a></code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/ffi/c_str.rs.html#802-805' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Performs the conversion.</p>
</div></div><h3 id='impl-From%3CIntoInnerError%3CW%3E%3E' class='impl'><span class='in-band'><table class='table-display'><tbody><tr><td><code>impl&lt;W&gt; <a class="trait" href="https://doc.rust-lang.org/nightly/core/convert/trait.From.html" title="trait core::convert::From">From</a>&lt;<a class="struct" href="https://doc.rust-lang.org/nightly/std/io/buffered/struct.IntoInnerError.html" title="struct std::io::buffered::IntoInnerError">IntoInnerError</a>&lt;W&gt;&gt; for <a class="struct" href="../../tokio/io/struct.Error.html" title="struct tokio::io::Error">Error</a></code><a href='#impl-From%3CIntoInnerError%3CW%3E%3E' class='anchor'></a></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/buffered.rs.html#688-690' title='goto source code'>[src]</a></span></td></tr></tbody></table></h3><div class='impl-items'><h4 id='method.from-2' class="method"><span id='from.v-2' class='invisible'><table class='table-display'><tbody><tr><td><code>fn <a href='https://doc.rust-lang.org/nightly/core/convert/trait.From.html#tymethod.from' class='fnname'>from</a>(iie: <a class="struct" href="https://doc.rust-lang.org/nightly/std/io/buffered/struct.IntoInnerError.html" title="struct std::io::buffered::IntoInnerError">IntoInnerError</a>&lt;W&gt;) -&gt; <a class="struct" href="../../tokio/io/struct.Error.html" title="struct tokio::io::Error">Error</a></code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/buffered.rs.html#689' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>Performs the conversion.</p>
</div></div><h3 id='impl-Error' class='impl'><span class='in-band'><table class='table-display'><tbody><tr><td><code>impl <a class="trait" href="https://doc.rust-lang.org/nightly/std/error/trait.Error.html" title="trait std::error::Error">Error</a> for <a class="struct" href="../../tokio/io/struct.Error.html" title="struct tokio::io::Error">Error</a></code><a href='#impl-Error' class='anchor'></a></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/error.rs.html#546-561' title='goto source code'>[src]</a></span></td></tr></tbody></table></h3><div class='impl-items'><h4 id='method.description' class="method"><span id='description.v' class='invisible'><table class='table-display'><tbody><tr><td><code>fn <a href='https://doc.rust-lang.org/nightly/std/error/trait.Error.html#tymethod.description' class='fnname'>description</a>(&amp;self) -&gt; &amp;<a class="primitive" href="https://doc.rust-lang.org/nightly/std/primitive.str.html">str</a></code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/error.rs.html#547-552' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>A short description of the error. <a href="https://doc.rust-lang.org/nightly/std/error/trait.Error.html#tymethod.description">Read more</a></p>
</div><h4 id='method.cause' class="method"><span id='cause.v' class='invisible'><table class='table-display'><tbody><tr><td><code>fn <a href='https://doc.rust-lang.org/nightly/std/error/trait.Error.html#method.cause' class='fnname'>cause</a>(&amp;self) -&gt; <a class="enum" href="https://doc.rust-lang.org/nightly/core/option/enum.Option.html" title="enum core::option::Option">Option</a>&lt;&amp;<a class="trait" href="https://doc.rust-lang.org/nightly/std/error/trait.Error.html" title="trait std::error::Error">Error</a>&gt;</code></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/error.rs.html#554-560' title='goto source code'>[src]</a></td></tr></tbody></table></span></h4><div class='docblock'><p>The lower-level cause of this error, if any. <a href="https://doc.rust-lang.org/nightly/std/error/trait.Error.html#method.cause">Read more</a></p>
</div></div><h3 id='impl-Debug' class='impl'><span class='in-band'><table class='table-display'><tbody><tr><td><code>impl <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="struct" href="../../tokio/io/struct.Error.html" title="struct tokio::io::Error">Error</a></code><a href='#impl-Debug' class='anchor'></a></span></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/error.rs.html#71-75' title='goto source code'>[src]</a></span></td></tr></tbody></table></h3><div class='impl-items'><h4 id='method.fmt-1' class="method"><span id='fmt.v-1' class='invisible'><table class='table-display'><tbody><tr><td><code>fn <a href='https://doc.rust-lang.org/nightly/core/fmt/trait.Debug.html#tymethod.fmt' class='fnname'>fmt</a>(&amp;self, f: &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></td><td><span class='out-of-band'><div class='ghost'></div><a class='srclink' href='https://doc.rust-lang.org/nightly/src/std/io/error.rs.html#72-74' title='goto source code'>[src]</a></td></tr></tbody></table></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></div>
<h2 id='synthetic-implementations' class='small-section-header'>
Auto Trait Implementations<a href='#synthetic-implementations' class='anchor'></a>
</h2>
<div id='synthetic-implementations-list'>
<h3 id='impl-Send' class='impl'><span class='in-band'><table class='table-display'><tbody><tr><td><code>impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Send.html" title="trait core::marker::Send">Send</a> for <a class="struct" href="../../tokio/io/struct.Error.html" title="struct tokio::io::Error">Error</a></code><a href='#impl-Send' class='anchor'></a></span></td><td><span class='out-of-band'></span></td></tr></tbody></table></h3><div class='impl-items'></div><h3 id='impl-Sync' class='impl'><span class='in-band'><table class='table-display'><tbody><tr><td><code>impl <a class="trait" href="https://doc.rust-lang.org/nightly/core/marker/trait.Sync.html" title="trait core::marker::Sync">Sync</a> for <a class="struct" href="../../tokio/io/struct.Error.html" title="struct tokio::io::Error">Error</a></code><a href='#impl-Sync' class='anchor'></a></span></td><td><span class='out-of-band'></span></td></tr></tbody></table></h3><div class='impl-items'></div></div></section>
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