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</pre><pre class="rust ">
<span class="comment">// Copyright 2015 The Rust Project Developers. See the COPYRIGHT</span>
<span class="comment">// file at the top-level directory of this distribution and at</span>
<span class="comment">// http://rust-lang.org/COPYRIGHT.</span>
<span class="comment">//</span>
<span class="comment">// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or</span>
<span class="comment">// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license</span>
<span class="comment">// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your</span>
<span class="comment">// option. This file may not be copied, modified, or distributed</span>
<span class="comment">// except according to those terms.</span>
<span class="kw">use</span> <span class="ident">error</span>;
<span class="kw">use</span> <span class="ident">fmt</span>;
<span class="kw">use</span> <span class="ident">result</span>;
<span class="kw">use</span> <span class="ident">sys</span>;
<span class="kw">use</span> <span class="ident">convert</span>::<span class="ident">From</span>;
<span class="doccomment">/// A specialized [`Result`](../result/enum.Result.html) type for I/O</span>
<span class="doccomment">/// operations.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This type is broadly used across `std::io` for any operation which may</span>
<span class="doccomment">/// produce an error.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This typedef is generally used to avoid writing out `io::Error` directly and</span>
<span class="doccomment">/// is otherwise a direct mapping to `Result`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// While usual Rust style is to import types directly, aliases of `Result`</span>
<span class="doccomment">/// often are not, to make it easier to distinguish between them. `Result` is</span>
<span class="doccomment">/// generally assumed to be `std::result::Result`, and so users of this alias</span>
<span class="doccomment">/// will generally use `io::Result` instead of shadowing the prelude's import</span>
<span class="doccomment">/// of `std::result::Result`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// A convenience function that bubbles an `io::Result` to its caller:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use std::io;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// fn get_string() -> io::Result<String> {</span>
<span class="doccomment">/// let mut buffer = String::new();</span>
<span class="doccomment">///</span>
<span class="doccomment">/// io::stdin().read_line(&mut buffer)?;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Ok(buffer)</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">pub</span> <span class="kw">type</span> <span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="op">=</span> <span class="ident">result</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">T</span>, <span class="ident">Error</span><span class="op">></span>;
<span class="doccomment">/// The error type for I/O operations of the `Read`, `Write`, `Seek`, and</span>
<span class="doccomment">/// associated traits.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Errors mostly originate from the underlying OS, but custom instances of</span>
<span class="doccomment">/// `Error` can be created with crafted error messages and a particular value of</span>
<span class="doccomment">/// [`ErrorKind`].</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`ErrorKind`]: enum.ErrorKind.html</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>)]</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">Error</span> {
<span class="ident">repr</span>: <span class="ident">Repr</span>,
}
<span class="kw">enum</span> <span class="ident">Repr</span> {
<span class="ident">Os</span>(<span class="ident">i32</span>),
<span class="ident">Simple</span>(<span class="ident">ErrorKind</span>),
<span class="ident">Custom</span>(<span class="ident">Box</span><span class="op"><</span><span class="ident">Custom</span><span class="op">></span>),
}
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>)]</span>
<span class="kw">struct</span> <span class="ident">Custom</span> {
<span class="ident">kind</span>: <span class="ident">ErrorKind</span>,
<span class="ident">error</span>: <span class="ident">Box</span><span class="op"><</span><span class="ident">error</span>::<span class="ident">Error</span><span class="op">+</span><span class="ident">Send</span><span class="op">+</span><span class="ident">Sync</span><span class="op">></span>,
}
<span class="doccomment">/// A list specifying general categories of I/O error.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This list is intended to grow over time and it is not recommended to</span>
<span class="doccomment">/// exhaustively match against it.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// It is used with the [`io::Error`] type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`io::Error`]: struct.Error.html</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Clone</span>, <span class="ident">Copy</span>, <span class="ident">Debug</span>, <span class="ident">Eq</span>, <span class="ident">Hash</span>, <span class="ident">Ord</span>, <span class="ident">PartialEq</span>, <span class="ident">PartialOrd</span>)]</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="attribute">#[<span class="ident">allow</span>(<span class="ident">deprecated</span>)]</span>
<span class="kw">pub</span> <span class="kw">enum</span> <span class="ident">ErrorKind</span> {
<span class="doccomment">/// An entity was not found, often a file.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">NotFound</span>,
<span class="doccomment">/// The operation lacked the necessary privileges to complete.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">PermissionDenied</span>,
<span class="doccomment">/// The connection was refused by the remote server.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">ConnectionRefused</span>,
<span class="doccomment">/// The connection was reset by the remote server.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">ConnectionReset</span>,
<span class="doccomment">/// The connection was aborted (terminated) by the remote server.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">ConnectionAborted</span>,
<span class="doccomment">/// The network operation failed because it was not connected yet.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">NotConnected</span>,
<span class="doccomment">/// A socket address could not be bound because the address is already in</span>
<span class="doccomment">/// use elsewhere.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">AddrInUse</span>,
<span class="doccomment">/// A nonexistent interface was requested or the requested address was not</span>
<span class="doccomment">/// local.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">AddrNotAvailable</span>,
<span class="doccomment">/// The operation failed because a pipe was closed.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">BrokenPipe</span>,
<span class="doccomment">/// An entity already exists, often a file.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">AlreadyExists</span>,
<span class="doccomment">/// The operation needs to block to complete, but the blocking operation was</span>
<span class="doccomment">/// requested to not occur.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">WouldBlock</span>,
<span class="doccomment">/// A parameter was incorrect.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">InvalidInput</span>,
<span class="doccomment">/// Data not valid for the operation were encountered.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Unlike [`InvalidInput`], this typically means that the operation</span>
<span class="doccomment">/// parameters were valid, however the error was caused by malformed</span>
<span class="doccomment">/// input data.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// For example, a function that reads a file into a string will error with</span>
<span class="doccomment">/// `InvalidData` if the file's contents are not valid UTF-8.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`InvalidInput`]: #variant.InvalidInput</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"io_invalid_data"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.2.0"</span>)]</span>
<span class="ident">InvalidData</span>,
<span class="doccomment">/// The I/O operation's timeout expired, causing it to be canceled.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">TimedOut</span>,
<span class="doccomment">/// An error returned when an operation could not be completed because a</span>
<span class="doccomment">/// call to [`write`] returned [`Ok(0)`].</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This typically means that an operation could only succeed if it wrote a</span>
<span class="doccomment">/// particular number of bytes but only a smaller number of bytes could be</span>
<span class="doccomment">/// written.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`write`]: ../../std/io/trait.Write.html#tymethod.write</span>
<span class="doccomment">/// [`Ok(0)`]: ../../std/io/type.Result.html</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">WriteZero</span>,
<span class="doccomment">/// This operation was interrupted.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Interrupted operations can typically be retried.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">Interrupted</span>,
<span class="doccomment">/// Any I/O error not part of this list.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="ident">Other</span>,
<span class="doccomment">/// An error returned when an operation could not be completed because an</span>
<span class="doccomment">/// "end of file" was reached prematurely.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This typically means that an operation could only succeed if it read a</span>
<span class="doccomment">/// particular number of bytes but only a smaller number of bytes could be</span>
<span class="doccomment">/// read.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"read_exact"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.6.0"</span>)]</span>
<span class="ident">UnexpectedEof</span>,
<span class="doccomment">/// A marker variant that tells the compiler that users of this enum cannot</span>
<span class="doccomment">/// match it exhaustively.</span>
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"io_error_internals"</span>,
<span class="ident">reason</span> <span class="op">=</span> <span class="string">"better expressed through extensible enums that this \
enum cannot be exhaustively matched against"</span>,
<span class="ident">issue</span> <span class="op">=</span> <span class="string">"0"</span>)]</span>
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">hidden</span>)]</span>
<span class="ident">__Nonexhaustive</span>,
}
<span class="kw">impl</span> <span class="ident">ErrorKind</span> {
<span class="kw">fn</span> <span class="ident">as_str</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="kw-2">&</span><span class="lifetime">'static</span> <span class="ident">str</span> {
<span class="kw">match</span> <span class="kw-2">*</span><span class="self">self</span> {
<span class="ident">ErrorKind</span>::<span class="ident">NotFound</span> <span class="op">=></span> <span class="string">"entity not found"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">PermissionDenied</span> <span class="op">=></span> <span class="string">"permission denied"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">ConnectionRefused</span> <span class="op">=></span> <span class="string">"connection refused"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">ConnectionReset</span> <span class="op">=></span> <span class="string">"connection reset"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">ConnectionAborted</span> <span class="op">=></span> <span class="string">"connection aborted"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">NotConnected</span> <span class="op">=></span> <span class="string">"not connected"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">AddrInUse</span> <span class="op">=></span> <span class="string">"address in use"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">AddrNotAvailable</span> <span class="op">=></span> <span class="string">"address not available"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">BrokenPipe</span> <span class="op">=></span> <span class="string">"broken pipe"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">AlreadyExists</span> <span class="op">=></span> <span class="string">"entity already exists"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">WouldBlock</span> <span class="op">=></span> <span class="string">"operation would block"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">InvalidInput</span> <span class="op">=></span> <span class="string">"invalid input parameter"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">InvalidData</span> <span class="op">=></span> <span class="string">"invalid data"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">TimedOut</span> <span class="op">=></span> <span class="string">"timed out"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">WriteZero</span> <span class="op">=></span> <span class="string">"write zero"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">Interrupted</span> <span class="op">=></span> <span class="string">"operation interrupted"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">Other</span> <span class="op">=></span> <span class="string">"other os error"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">UnexpectedEof</span> <span class="op">=></span> <span class="string">"unexpected end of file"</span>,
<span class="ident">ErrorKind</span>::<span class="ident">__Nonexhaustive</span> <span class="op">=></span> <span class="macro">unreachable</span><span class="macro">!</span>()
}
}
}
<span class="doccomment">/// Intended for use for errors not exposed to the user, where allocating onto</span>
<span class="doccomment">/// the heap (for normal construction via Error::new) is too costly.</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"io_error_from_errorkind"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.14.0"</span>)]</span>
<span class="kw">impl</span> <span class="ident">From</span><span class="op"><</span><span class="ident">ErrorKind</span><span class="op">></span> <span class="kw">for</span> <span class="ident">Error</span> {
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">from</span>(<span class="ident">kind</span>: <span class="ident">ErrorKind</span>) <span class="op">-></span> <span class="ident">Error</span> {
<span class="ident">Error</span> {
<span class="ident">repr</span>: <span class="ident">Repr</span>::<span class="ident">Simple</span>(<span class="ident">kind</span>)
}
}
}
<span class="kw">impl</span> <span class="ident">Error</span> {
<span class="doccomment">/// Creates a new I/O error from a known kind of error as well as an</span>
<span class="doccomment">/// arbitrary error payload.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This function is used to generically create I/O errors which do not</span>
<span class="doccomment">/// originate from the OS itself. The `error` argument is an arbitrary</span>
<span class="doccomment">/// payload which will be contained in this `Error`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use std::io::{Error, ErrorKind};</span>
<span class="doccomment">///</span>
<span class="doccomment">/// // errors can be created from strings</span>
<span class="doccomment">/// let custom_error = Error::new(ErrorKind::Other, "oh no!");</span>
<span class="doccomment">///</span>
<span class="doccomment">/// // errors can also be created from other errors</span>
<span class="doccomment">/// let custom_error2 = Error::new(ErrorKind::Interrupted, custom_error);</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">new</span><span class="op"><</span><span class="ident">E</span><span class="op">></span>(<span class="ident">kind</span>: <span class="ident">ErrorKind</span>, <span class="ident">error</span>: <span class="ident">E</span>) <span class="op">-></span> <span class="ident">Error</span>
<span class="kw">where</span> <span class="ident">E</span>: <span class="ident">Into</span><span class="op"><</span><span class="ident">Box</span><span class="op"><</span><span class="ident">error</span>::<span class="ident">Error</span><span class="op">+</span><span class="ident">Send</span><span class="op">+</span><span class="ident">Sync</span><span class="op">>></span>
{
<span class="self">Self</span>::<span class="ident">_new</span>(<span class="ident">kind</span>, <span class="ident">error</span>.<span class="ident">into</span>())
}
<span class="kw">fn</span> <span class="ident">_new</span>(<span class="ident">kind</span>: <span class="ident">ErrorKind</span>, <span class="ident">error</span>: <span class="ident">Box</span><span class="op"><</span><span class="ident">error</span>::<span class="ident">Error</span><span class="op">+</span><span class="ident">Send</span><span class="op">+</span><span class="ident">Sync</span><span class="op">></span>) <span class="op">-></span> <span class="ident">Error</span> {
<span class="ident">Error</span> {
<span class="ident">repr</span>: <span class="ident">Repr</span>::<span class="ident">Custom</span>(<span class="ident">Box</span>::<span class="ident">new</span>(<span class="ident">Custom</span> {
<span class="ident">kind</span>: <span class="ident">kind</span>,
<span class="ident">error</span>: <span class="ident">error</span>,
}))
}
}
<span class="doccomment">/// Returns an error representing the last OS error which occurred.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This function reads the value of `errno` for the target platform (e.g.</span>
<span class="doccomment">/// `GetLastError` on Windows) and will return a corresponding instance of</span>
<span class="doccomment">/// `Error` for the error code.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use std::io::Error;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// println!("last OS error: {:?}", Error::last_os_error());</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">last_os_error</span>() <span class="op">-></span> <span class="ident">Error</span> {
<span class="ident">Error</span>::<span class="ident">from_raw_os_error</span>(<span class="ident">sys</span>::<span class="ident">os</span>::<span class="ident">errno</span>() <span class="kw">as</span> <span class="ident">i32</span>)
}
<span class="doccomment">/// Creates a new instance of an `Error` from a particular OS error code.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// On Linux:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// # if cfg!(target_os = "linux") {</span>
<span class="doccomment">/// use std::io;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let error = io::Error::from_raw_os_error(98);</span>
<span class="doccomment">/// assert_eq!(error.kind(), io::ErrorKind::AddrInUse);</span>
<span class="doccomment">/// # }</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">///</span>
<span class="doccomment">/// On Windows:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// # if cfg!(windows) {</span>
<span class="doccomment">/// use std::io;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let error = io::Error::from_raw_os_error(10048);</span>
<span class="doccomment">/// assert_eq!(error.kind(), io::ErrorKind::AddrInUse);</span>
<span class="doccomment">/// # }</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">from_raw_os_error</span>(<span class="ident">code</span>: <span class="ident">i32</span>) <span class="op">-></span> <span class="ident">Error</span> {
<span class="ident">Error</span> { <span class="ident">repr</span>: <span class="ident">Repr</span>::<span class="ident">Os</span>(<span class="ident">code</span>) }
}
<span class="doccomment">/// Returns the OS error that this error represents (if any).</span>
<span class="doccomment">///</span>
<span class="doccomment">/// If this `Error` was constructed via `last_os_error` or</span>
<span class="doccomment">/// `from_raw_os_error`, then this function will return `Some`, otherwise</span>
<span class="doccomment">/// it will return `None`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use std::io::{Error, ErrorKind};</span>
<span class="doccomment">///</span>
<span class="doccomment">/// fn print_os_error(err: &Error) {</span>
<span class="doccomment">/// if let Some(raw_os_err) = err.raw_os_error() {</span>
<span class="doccomment">/// println!("raw OS error: {:?}", raw_os_err);</span>
<span class="doccomment">/// } else {</span>
<span class="doccomment">/// println!("Not an OS error");</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// fn main() {</span>
<span class="doccomment">/// // Will print "raw OS error: ...".</span>
<span class="doccomment">/// print_os_error(&Error::last_os_error());</span>
<span class="doccomment">/// // Will print "Not an OS error".</span>
<span class="doccomment">/// print_os_error(&Error::new(ErrorKind::Other, "oh no!"));</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">raw_os_error</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="prelude-ty">Option</span><span class="op"><</span><span class="ident">i32</span><span class="op">></span> {
<span class="kw">match</span> <span class="self">self</span>.<span class="ident">repr</span> {
<span class="ident">Repr</span>::<span class="ident">Os</span>(<span class="ident">i</span>) <span class="op">=></span> <span class="prelude-val">Some</span>(<span class="ident">i</span>),
<span class="ident">Repr</span>::<span class="ident">Custom</span>(..) <span class="op">=></span> <span class="prelude-val">None</span>,
<span class="ident">Repr</span>::<span class="ident">Simple</span>(..) <span class="op">=></span> <span class="prelude-val">None</span>,
}
}
<span class="doccomment">/// Returns a reference to the inner error wrapped by this error (if any).</span>
<span class="doccomment">///</span>
<span class="doccomment">/// If this `Error` was constructed via `new` then this function will</span>
<span class="doccomment">/// return `Some`, otherwise it will return `None`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use std::io::{Error, ErrorKind};</span>
<span class="doccomment">///</span>
<span class="doccomment">/// fn print_error(err: &Error) {</span>
<span class="doccomment">/// if let Some(inner_err) = err.get_ref() {</span>
<span class="doccomment">/// println!("Inner error: {:?}", inner_err);</span>
<span class="doccomment">/// } else {</span>
<span class="doccomment">/// println!("No inner error");</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// fn main() {</span>
<span class="doccomment">/// // Will print "No inner error".</span>
<span class="doccomment">/// print_error(&Error::last_os_error());</span>
<span class="doccomment">/// // Will print "Inner error: ...".</span>
<span class="doccomment">/// print_error(&Error::new(ErrorKind::Other, "oh no!"));</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"io_error_inner"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.3.0"</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">get_ref</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="prelude-ty">Option</span><span class="op"><</span><span class="kw-2">&</span>(<span class="ident">error</span>::<span class="ident">Error</span><span class="op">+</span><span class="ident">Send</span><span class="op">+</span><span class="ident">Sync</span><span class="op">+</span><span class="lifetime">'static</span>)<span class="op">></span> {
<span class="kw">match</span> <span class="self">self</span>.<span class="ident">repr</span> {
<span class="ident">Repr</span>::<span class="ident">Os</span>(..) <span class="op">=></span> <span class="prelude-val">None</span>,
<span class="ident">Repr</span>::<span class="ident">Simple</span>(..) <span class="op">=></span> <span class="prelude-val">None</span>,
<span class="ident">Repr</span>::<span class="ident">Custom</span>(<span class="kw-2">ref</span> <span class="ident">c</span>) <span class="op">=></span> <span class="prelude-val">Some</span>(<span class="kw-2">&</span><span class="kw-2">*</span><span class="ident">c</span>.<span class="ident">error</span>),
}
}
<span class="doccomment">/// Returns a mutable reference to the inner error wrapped by this error</span>
<span class="doccomment">/// (if any).</span>
<span class="doccomment">///</span>
<span class="doccomment">/// If this `Error` was constructed via `new` then this function will</span>
<span class="doccomment">/// return `Some`, otherwise it will return `None`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use std::io::{Error, ErrorKind};</span>
<span class="doccomment">/// use std::{error, fmt};</span>
<span class="doccomment">/// use std::fmt::Display;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// #[derive(Debug)]</span>
<span class="doccomment">/// struct MyError {</span>
<span class="doccomment">/// v: String,</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// impl MyError {</span>
<span class="doccomment">/// fn new() -> MyError {</span>
<span class="doccomment">/// MyError {</span>
<span class="doccomment">/// v: "oh no!".to_string()</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// fn change_message(&mut self, new_message: &str) {</span>
<span class="doccomment">/// self.v = new_message.to_string();</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// impl error::Error for MyError {</span>
<span class="doccomment">/// fn description(&self) -> &str { &self.v }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// impl Display for MyError {</span>
<span class="doccomment">/// fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {</span>
<span class="doccomment">/// write!(f, "MyError: {}", &self.v)</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// fn change_error(mut err: Error) -> Error {</span>
<span class="doccomment">/// if let Some(inner_err) = err.get_mut() {</span>
<span class="doccomment">/// inner_err.downcast_mut::<MyError>().unwrap().change_message("I've been changed!");</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// err</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// fn print_error(err: &Error) {</span>
<span class="doccomment">/// if let Some(inner_err) = err.get_ref() {</span>
<span class="doccomment">/// println!("Inner error: {}", inner_err);</span>
<span class="doccomment">/// } else {</span>
<span class="doccomment">/// println!("No inner error");</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// fn main() {</span>
<span class="doccomment">/// // Will print "No inner error".</span>
<span class="doccomment">/// print_error(&change_error(Error::last_os_error()));</span>
<span class="doccomment">/// // Will print "Inner error: ...".</span>
<span class="doccomment">/// print_error(&change_error(Error::new(ErrorKind::Other, MyError::new())));</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"io_error_inner"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.3.0"</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">get_mut</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-></span> <span class="prelude-ty">Option</span><span class="op"><</span><span class="kw-2">&</span><span class="kw-2">mut</span> (<span class="ident">error</span>::<span class="ident">Error</span><span class="op">+</span><span class="ident">Send</span><span class="op">+</span><span class="ident">Sync</span><span class="op">+</span><span class="lifetime">'static</span>)<span class="op">></span> {
<span class="kw">match</span> <span class="self">self</span>.<span class="ident">repr</span> {
<span class="ident">Repr</span>::<span class="ident">Os</span>(..) <span class="op">=></span> <span class="prelude-val">None</span>,
<span class="ident">Repr</span>::<span class="ident">Simple</span>(..) <span class="op">=></span> <span class="prelude-val">None</span>,
<span class="ident">Repr</span>::<span class="ident">Custom</span>(<span class="kw-2">ref</span> <span class="kw-2">mut</span> <span class="ident">c</span>) <span class="op">=></span> <span class="prelude-val">Some</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="kw-2">*</span><span class="ident">c</span>.<span class="ident">error</span>),
}
}
<span class="doccomment">/// Consumes the `Error`, returning its inner error (if any).</span>
<span class="doccomment">///</span>
<span class="doccomment">/// If this `Error` was constructed via `new` then this function will</span>
<span class="doccomment">/// return `Some`, otherwise it will return `None`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use std::io::{Error, ErrorKind};</span>
<span class="doccomment">///</span>
<span class="doccomment">/// fn print_error(err: Error) {</span>
<span class="doccomment">/// if let Some(inner_err) = err.into_inner() {</span>
<span class="doccomment">/// println!("Inner error: {}", inner_err);</span>
<span class="doccomment">/// } else {</span>
<span class="doccomment">/// println!("No inner error");</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// fn main() {</span>
<span class="doccomment">/// // Will print "No inner error".</span>
<span class="doccomment">/// print_error(Error::last_os_error());</span>
<span class="doccomment">/// // Will print "Inner error: ...".</span>
<span class="doccomment">/// print_error(Error::new(ErrorKind::Other, "oh no!"));</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"io_error_inner"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.3.0"</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">into_inner</span>(<span class="self">self</span>) <span class="op">-></span> <span class="prelude-ty">Option</span><span class="op"><</span><span class="ident">Box</span><span class="op"><</span><span class="ident">error</span>::<span class="ident">Error</span><span class="op">+</span><span class="ident">Send</span><span class="op">+</span><span class="ident">Sync</span><span class="op">>></span> {
<span class="kw">match</span> <span class="self">self</span>.<span class="ident">repr</span> {
<span class="ident">Repr</span>::<span class="ident">Os</span>(..) <span class="op">=></span> <span class="prelude-val">None</span>,
<span class="ident">Repr</span>::<span class="ident">Simple</span>(..) <span class="op">=></span> <span class="prelude-val">None</span>,
<span class="ident">Repr</span>::<span class="ident">Custom</span>(<span class="ident">c</span>) <span class="op">=></span> <span class="prelude-val">Some</span>(<span class="ident">c</span>.<span class="ident">error</span>)
}
}
<span class="doccomment">/// Returns the corresponding `ErrorKind` for this error.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use std::io::{Error, ErrorKind};</span>
<span class="doccomment">///</span>
<span class="doccomment">/// fn print_error(err: Error) {</span>
<span class="doccomment">/// println!("{:?}", err.kind());</span>
<span class="doccomment">/// }</span>
<span class="doccomment">///</span>
<span class="doccomment">/// fn main() {</span>
<span class="doccomment">/// // Will print "No inner error".</span>
<span class="doccomment">/// print_error(Error::last_os_error());</span>
<span class="doccomment">/// // Will print "Inner error: ...".</span>
<span class="doccomment">/// print_error(Error::new(ErrorKind::AddrInUse, "oh no!"));</span>
<span class="doccomment">/// }</span>
<span class="doccomment">/// ```</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">kind</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">ErrorKind</span> {
<span class="kw">match</span> <span class="self">self</span>.<span class="ident">repr</span> {
<span class="ident">Repr</span>::<span class="ident">Os</span>(<span class="ident">code</span>) <span class="op">=></span> <span class="ident">sys</span>::<span class="ident">decode_error_kind</span>(<span class="ident">code</span>),
<span class="ident">Repr</span>::<span class="ident">Custom</span>(<span class="kw-2">ref</span> <span class="ident">c</span>) <span class="op">=></span> <span class="ident">c</span>.<span class="ident">kind</span>,
<span class="ident">Repr</span>::<span class="ident">Simple</span>(<span class="ident">kind</span>) <span class="op">=></span> <span class="ident">kind</span>,
}
}
}
<span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">Repr</span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">fmt</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
<span class="kw">match</span> <span class="kw-2">*</span><span class="self">self</span> {
<span class="ident">Repr</span>::<span class="ident">Os</span>(<span class="kw-2">ref</span> <span class="ident">code</span>) <span class="op">=></span>
<span class="ident">fmt</span>.<span class="ident">debug_struct</span>(<span class="string">"Os"</span>).<span class="ident">field</span>(<span class="string">"code"</span>, <span class="ident">code</span>)
.<span class="ident">field</span>(<span class="string">"message"</span>, <span class="kw-2">&</span><span class="ident">sys</span>::<span class="ident">os</span>::<span class="ident">error_string</span>(<span class="kw-2">*</span><span class="ident">code</span>)).<span class="ident">finish</span>(),
<span class="ident">Repr</span>::<span class="ident">Custom</span>(<span class="kw-2">ref</span> <span class="ident">c</span>) <span class="op">=></span> <span class="ident">fmt</span>.<span class="ident">debug_tuple</span>(<span class="string">"Custom"</span>).<span class="ident">field</span>(<span class="ident">c</span>).<span class="ident">finish</span>(),
<span class="ident">Repr</span>::<span class="ident">Simple</span>(<span class="ident">kind</span>) <span class="op">=></span> <span class="ident">fmt</span>.<span class="ident">debug_tuple</span>(<span class="string">"Kind"</span>).<span class="ident">field</span>(<span class="kw-2">&</span><span class="ident">kind</span>).<span class="ident">finish</span>(),
}
}
}
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Display</span> <span class="kw">for</span> <span class="ident">Error</span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">fmt</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
<span class="kw">match</span> <span class="self">self</span>.<span class="ident">repr</span> {
<span class="ident">Repr</span>::<span class="ident">Os</span>(<span class="ident">code</span>) <span class="op">=></span> {
<span class="kw">let</span> <span class="ident">detail</span> <span class="op">=</span> <span class="ident">sys</span>::<span class="ident">os</span>::<span class="ident">error_string</span>(<span class="ident">code</span>);
<span class="macro">write</span><span class="macro">!</span>(<span class="ident">fmt</span>, <span class="string">"{} (os error {})"</span>, <span class="ident">detail</span>, <span class="ident">code</span>)
}
<span class="ident">Repr</span>::<span class="ident">Custom</span>(<span class="kw-2">ref</span> <span class="ident">c</span>) <span class="op">=></span> <span class="ident">c</span>.<span class="ident">error</span>.<span class="ident">fmt</span>(<span class="ident">fmt</span>),
<span class="ident">Repr</span>::<span class="ident">Simple</span>(<span class="ident">kind</span>) <span class="op">=></span> <span class="macro">write</span><span class="macro">!</span>(<span class="ident">fmt</span>, <span class="string">"{}"</span>, <span class="ident">kind</span>.<span class="ident">as_str</span>()),
}
}
}
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"rust1"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.0.0"</span>)]</span>
<span class="kw">impl</span> <span class="ident">error</span>::<span class="ident">Error</span> <span class="kw">for</span> <span class="ident">Error</span> {
<span class="kw">fn</span> <span class="ident">description</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="kw-2">&</span><span class="ident">str</span> {
<span class="kw">match</span> <span class="self">self</span>.<span class="ident">repr</span> {
<span class="ident">Repr</span>::<span class="ident">Os</span>(..) <span class="op">|</span> <span class="ident">Repr</span>::<span class="ident">Simple</span>(..) <span class="op">=></span> <span class="self">self</span>.<span class="ident">kind</span>().<span class="ident">as_str</span>(),
<span class="ident">Repr</span>::<span class="ident">Custom</span>(<span class="kw-2">ref</span> <span class="ident">c</span>) <span class="op">=></span> <span class="ident">c</span>.<span class="ident">error</span>.<span class="ident">description</span>(),
}
}
<span class="kw">fn</span> <span class="ident">cause</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="prelude-ty">Option</span><span class="op"><</span><span class="kw-2">&</span><span class="ident">error</span>::<span class="ident">Error</span><span class="op">></span> {
<span class="kw">match</span> <span class="self">self</span>.<span class="ident">repr</span> {
<span class="ident">Repr</span>::<span class="ident">Os</span>(..) <span class="op">=></span> <span class="prelude-val">None</span>,
<span class="ident">Repr</span>::<span class="ident">Simple</span>(..) <span class="op">=></span> <span class="prelude-val">None</span>,
<span class="ident">Repr</span>::<span class="ident">Custom</span>(<span class="kw-2">ref</span> <span class="ident">c</span>) <span class="op">=></span> <span class="ident">c</span>.<span class="ident">error</span>.<span class="ident">cause</span>(),
}
}
}
<span class="kw">fn</span> <span class="ident">_assert_error_is_sync_send</span>() {
<span class="kw">fn</span> <span class="ident">_is_sync_send</span><span class="op"><</span><span class="ident">T</span>: <span class="ident">Sync</span><span class="op">+</span><span class="ident">Send</span><span class="op">></span>() {}
<span class="ident">_is_sync_send</span>::<span class="op"><</span><span class="ident">Error</span><span class="op">></span>();
}
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">test</span>)]</span>
<span class="kw">mod</span> <span class="ident">test</span> {
<span class="kw">use</span> <span class="kw">super</span>::{<span class="ident">Error</span>, <span class="ident">ErrorKind</span>};
<span class="kw">use</span> <span class="ident">error</span>;
<span class="kw">use</span> <span class="ident">fmt</span>;
<span class="kw">use</span> <span class="ident">sys</span>::<span class="ident">os</span>::<span class="ident">error_string</span>;
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="kw">fn</span> <span class="ident">test_debug_error</span>() {
<span class="kw">let</span> <span class="ident">code</span> <span class="op">=</span> <span class="number">6</span>;
<span class="kw">let</span> <span class="ident">msg</span> <span class="op">=</span> <span class="ident">error_string</span>(<span class="ident">code</span>);
<span class="kw">let</span> <span class="ident">err</span> <span class="op">=</span> <span class="ident">Error</span> { <span class="ident">repr</span>: <span class="kw">super</span>::<span class="ident">Repr</span>::<span class="ident">Os</span>(<span class="ident">code</span>) };
<span class="kw">let</span> <span class="ident">expected</span> <span class="op">=</span> <span class="macro">format</span><span class="macro">!</span>(<span class="string">"Error {{ repr: Os {{ code: {:?}, message: {:?} }} }}"</span>, <span class="ident">code</span>, <span class="ident">msg</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="macro">format</span><span class="macro">!</span>(<span class="string">"{:?}"</span>, <span class="ident">err</span>), <span class="ident">expected</span>);
}
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="kw">fn</span> <span class="ident">test_downcasting</span>() {
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>)]</span>
<span class="kw">struct</span> <span class="ident">TestError</span>;
<span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Display</span> <span class="kw">for</span> <span class="ident">TestError</span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, _: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
<span class="prelude-val">Ok</span>(())
}
}
<span class="kw">impl</span> <span class="ident">error</span>::<span class="ident">Error</span> <span class="kw">for</span> <span class="ident">TestError</span> {
<span class="kw">fn</span> <span class="ident">description</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="kw-2">&</span><span class="ident">str</span> {
<span class="string">"asdf"</span>
}
}
<span class="comment">// we have to call all of these UFCS style right now since method</span>
<span class="comment">// resolution won't implicitly drop the Send+Sync bounds</span>
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">err</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="ident">TestError</span>);
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">err</span>.<span class="ident">get_ref</span>().<span class="ident">unwrap</span>().<span class="ident">is</span>::<span class="op"><</span><span class="ident">TestError</span><span class="op">></span>());
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="string">"asdf"</span>, <span class="ident">err</span>.<span class="ident">get_ref</span>().<span class="ident">unwrap</span>().<span class="ident">description</span>());
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">err</span>.<span class="ident">get_mut</span>().<span class="ident">unwrap</span>().<span class="ident">is</span>::<span class="op"><</span><span class="ident">TestError</span><span class="op">></span>());
<span class="kw">let</span> <span class="ident">extracted</span> <span class="op">=</span> <span class="ident">err</span>.<span class="ident">into_inner</span>().<span class="ident">unwrap</span>();
<span class="ident">extracted</span>.<span class="ident">downcast</span>::<span class="op"><</span><span class="ident">TestError</span><span class="op">></span>().<span class="ident">unwrap</span>();
}
}
</pre>
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