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</pre><pre class="rust ">
<span class="comment">// Copyright 2014 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="attribute">#![<span class="ident">allow</span>(<span class="ident">missing_copy_implementations</span>)]</span>
<span class="kw">use</span> <span class="ident">fmt</span>;
<span class="kw">use</span> <span class="ident">io</span>::{<span class="self">self</span>, <span class="ident">Read</span>, <span class="ident">Initializer</span>, <span class="ident">Write</span>, <span class="ident">ErrorKind</span>, <span class="ident">BufRead</span>};
<span class="kw">use</span> <span class="ident">mem</span>;
<span class="doccomment">/// Copies the entire contents of a reader into a writer.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This function will continuously read data from `reader` and then</span>
<span class="doccomment">/// write it into `writer` in a streaming fashion until `reader`</span>
<span class="doccomment">/// returns EOF.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// On success, the total number of bytes that were copied from</span>
<span class="doccomment">/// `reader` to `writer` is returned.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Errors</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This function will return an error immediately if any call to `read` or</span>
<span class="doccomment">/// `write` returns an error. All instances of `ErrorKind::Interrupted` are</span>
<span class="doccomment">/// handled by this function and the underlying operation is retried.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use std::io;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # fn foo() -> io::Result<()> {</span>
<span class="doccomment">/// let mut reader: &[u8] = b"hello";</span>
<span class="doccomment">/// let mut writer: Vec<u8> = vec![];</span>
<span class="doccomment">///</span>
<span class="doccomment">/// io::copy(&mut reader, &mut writer)?;</span>
<span class="doccomment">///</span>
<span class="doccomment">/// assert_eq!(&b"hello"[..], &writer[..]);</span>
<span class="doccomment">/// # Ok(())</span>
<span class="doccomment">/// # }</span>
<span class="doccomment">/// # foo().unwrap();</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">copy</span><span class="op"><</span><span class="ident">R</span>: <span class="question-mark">?</span><span class="ident">Sized</span>, <span class="ident">W</span>: <span class="question-mark">?</span><span class="ident">Sized</span><span class="op">></span>(<span class="ident">reader</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">R</span>, <span class="ident">writer</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">W</span>) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">u64</span><span class="op">></span>
<span class="kw">where</span> <span class="ident">R</span>: <span class="ident">Read</span>, <span class="ident">W</span>: <span class="ident">Write</span>
{
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">buf</span> <span class="op">=</span> <span class="kw">unsafe</span> {
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">buf</span>: [<span class="ident">u8</span>; <span class="kw">super</span>::<span class="ident">DEFAULT_BUF_SIZE</span>] <span class="op">=</span> <span class="ident">mem</span>::<span class="ident">uninitialized</span>();
<span class="ident">reader</span>.<span class="ident">initializer</span>().<span class="ident">initialize</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">buf</span>);
<span class="ident">buf</span>
};
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">written</span> <span class="op">=</span> <span class="number">0</span>;
<span class="kw">loop</span> {
<span class="kw">let</span> <span class="ident">len</span> <span class="op">=</span> <span class="kw">match</span> <span class="ident">reader</span>.<span class="ident">read</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">buf</span>) {
<span class="prelude-val">Ok</span>(<span class="number">0</span>) <span class="op">=></span> <span class="kw">return</span> <span class="prelude-val">Ok</span>(<span class="ident">written</span>),
<span class="prelude-val">Ok</span>(<span class="ident">len</span>) <span class="op">=></span> <span class="ident">len</span>,
<span class="prelude-val">Err</span>(<span class="kw-2">ref</span> <span class="ident">e</span>) <span class="kw">if</span> <span class="ident">e</span>.<span class="ident">kind</span>() <span class="op">==</span> <span class="ident">ErrorKind</span>::<span class="ident">Interrupted</span> <span class="op">=></span> <span class="kw">continue</span>,
<span class="prelude-val">Err</span>(<span class="ident">e</span>) <span class="op">=></span> <span class="kw">return</span> <span class="prelude-val">Err</span>(<span class="ident">e</span>),
};
<span class="ident">writer</span>.<span class="ident">write_all</span>(<span class="kw-2">&</span><span class="ident">buf</span>[..<span class="ident">len</span>])<span class="question-mark">?</span>;
<span class="ident">written</span> <span class="op">+=</span> <span class="ident">len</span> <span class="kw">as</span> <span class="ident">u64</span>;
}
}
<span class="doccomment">/// A reader which is always at EOF.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This struct is generally created by calling [`empty`]. Please see</span>
<span class="doccomment">/// the documentation of [`empty()`][`empty`] for more details.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`empty`]: fn.empty.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="kw">pub</span> <span class="kw">struct</span> <span class="ident">Empty</span> { <span class="ident">_priv</span>: () }
<span class="doccomment">/// Constructs a new handle to an empty reader.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// All reads from the returned reader will return [`Ok`]`(0)`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [`Ok`]: ../result/enum.Result.html#variant.Ok</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// A slightly sad example of not reading anything into a buffer:</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use std::io::{self, Read};</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let mut buffer = String::new();</span>
<span class="doccomment">/// io::empty().read_to_string(&mut buffer).unwrap();</span>
<span class="doccomment">/// assert!(buffer.is_empty());</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">empty</span>() <span class="op">-></span> <span class="ident">Empty</span> { <span class="ident">Empty</span> { <span class="ident">_priv</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">Read</span> <span class="kw">for</span> <span class="ident">Empty</span> {
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">read</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">_buf</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> [<span class="ident">u8</span>]) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">usize</span><span class="op">></span> { <span class="prelude-val">Ok</span>(<span class="number">0</span>) }
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">initializer</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">Initializer</span> {
<span class="ident">Initializer</span>::<span class="ident">nop</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">BufRead</span> <span class="kw">for</span> <span class="ident">Empty</span> {
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">fill_buf</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="kw-2">&</span>[<span class="ident">u8</span>]<span class="op">></span> { <span class="prelude-val">Ok</span>(<span class="kw-2">&</span>[]) }
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">consume</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">_n</span>: <span class="ident">usize</span>) {}
}
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"std_debug"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.16.0"</span>)]</span>
<span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">Empty</span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</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="ident">f</span>.<span class="ident">pad</span>(<span class="string">"Empty { .. }"</span>)
}
}
<span class="doccomment">/// A reader which yields one byte over and over and over and over and over and...</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This struct is generally created by calling [`repeat`][repeat]. Please</span>
<span class="doccomment">/// see the documentation of `repeat()` for more details.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [repeat]: fn.repeat.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="kw">pub</span> <span class="kw">struct</span> <span class="ident">Repeat</span> { <span class="ident">byte</span>: <span class="ident">u8</span> }
<span class="doccomment">/// Creates an instance of a reader that infinitely repeats one byte.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// All reads from this reader will succeed by filling the specified buffer with</span>
<span class="doccomment">/// the given byte.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```</span>
<span class="doccomment">/// use std::io::{self, Read};</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let mut buffer = [0; 3];</span>
<span class="doccomment">/// io::repeat(0b101).read_exact(&mut buffer).unwrap();</span>
<span class="doccomment">/// assert_eq!(buffer, [0b101, 0b101, 0b101]);</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">repeat</span>(<span class="ident">byte</span>: <span class="ident">u8</span>) <span class="op">-></span> <span class="ident">Repeat</span> { <span class="ident">Repeat</span> { <span class="ident">byte</span>: <span class="ident">byte</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">Read</span> <span class="kw">for</span> <span class="ident">Repeat</span> {
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">read</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">buf</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> [<span class="ident">u8</span>]) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">usize</span><span class="op">></span> {
<span class="kw">for</span> <span class="ident">slot</span> <span class="kw">in</span> <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="kw-2">*</span><span class="ident">buf</span> {
<span class="kw-2">*</span><span class="ident">slot</span> <span class="op">=</span> <span class="self">self</span>.<span class="ident">byte</span>;
}
<span class="prelude-val">Ok</span>(<span class="ident">buf</span>.<span class="ident">len</span>())
}
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">initializer</span>(<span class="kw-2">&</span><span class="self">self</span>) <span class="op">-></span> <span class="ident">Initializer</span> {
<span class="ident">Initializer</span>::<span class="ident">nop</span>()
}
}
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"std_debug"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.16.0"</span>)]</span>
<span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">Repeat</span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</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="ident">f</span>.<span class="ident">pad</span>(<span class="string">"Repeat { .. }"</span>)
}
}
<span class="doccomment">/// A writer which will move data into the void.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// This struct is generally created by calling [`sink`][sink]. Please</span>
<span class="doccomment">/// see the documentation of `sink()` for more details.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [sink]: fn.sink.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="kw">pub</span> <span class="kw">struct</span> <span class="ident">Sink</span> { <span class="ident">_priv</span>: () }
<span class="doccomment">/// Creates an instance of a writer which will successfully consume all data.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// All calls to `write` on the returned instance will return `Ok(buf.len())`</span>
<span class="doccomment">/// and the contents of the buffer will not be inspected.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// # Examples</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ```rust</span>
<span class="doccomment">/// use std::io::{self, Write};</span>
<span class="doccomment">///</span>
<span class="doccomment">/// let buffer = vec![1, 2, 3, 5, 8];</span>
<span class="doccomment">/// let num_bytes = io::sink().write(&buffer).unwrap();</span>
<span class="doccomment">/// assert_eq!(num_bytes, 5);</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">sink</span>() <span class="op">-></span> <span class="ident">Sink</span> { <span class="ident">Sink</span> { <span class="ident">_priv</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">Write</span> <span class="kw">for</span> <span class="ident">Sink</span> {
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">write</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>, <span class="ident">buf</span>: <span class="kw-2">&</span>[<span class="ident">u8</span>]) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span><span class="ident">usize</span><span class="op">></span> { <span class="prelude-val">Ok</span>(<span class="ident">buf</span>.<span class="ident">len</span>()) }
<span class="attribute">#[<span class="ident">inline</span>]</span>
<span class="kw">fn</span> <span class="ident">flush</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-></span> <span class="ident">io</span>::<span class="prelude-ty">Result</span><span class="op"><</span>()<span class="op">></span> { <span class="prelude-val">Ok</span>(()) }
}
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"std_debug"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.16.0"</span>)]</span>
<span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">Sink</span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</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="ident">f</span>.<span class="ident">pad</span>(<span class="string">"Sink { .. }"</span>)
}
}
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">test</span>)]</span>
<span class="kw">mod</span> <span class="ident">tests</span> {
<span class="kw">use</span> <span class="ident">io</span>::<span class="ident">prelude</span>::<span class="kw-2">*</span>;
<span class="kw">use</span> <span class="ident">io</span>::{<span class="ident">copy</span>, <span class="ident">sink</span>, <span class="ident">empty</span>, <span class="ident">repeat</span>};
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="kw">fn</span> <span class="ident">copy_copies</span>() {
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">r</span> <span class="op">=</span> <span class="ident">repeat</span>(<span class="number">0</span>).<span class="ident">take</span>(<span class="number">4</span>);
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">w</span> <span class="op">=</span> <span class="ident">sink</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">copy</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">r</span>, <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">w</span>).<span class="ident">unwrap</span>(), <span class="number">4</span>);
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">r</span> <span class="op">=</span> <span class="ident">repeat</span>(<span class="number">0</span>).<span class="ident">take</span>(<span class="number">1</span> <span class="op"><<</span> <span class="number">17</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">copy</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">r</span> <span class="kw">as</span> <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">Read</span>, <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">w</span> <span class="kw">as</span> <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">Write</span>).<span class="ident">unwrap</span>(), <span class="number">1</span> <span class="op"><<</span> <span class="number">17</span>);
}
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="kw">fn</span> <span class="ident">sink_sinks</span>() {
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">s</span> <span class="op">=</span> <span class="ident">sink</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">s</span>.<span class="ident">write</span>(<span class="kw-2">&</span>[]).<span class="ident">unwrap</span>(), <span class="number">0</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">s</span>.<span class="ident">write</span>(<span class="kw-2">&</span>[<span class="number">0</span>]).<span class="ident">unwrap</span>(), <span class="number">1</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">s</span>.<span class="ident">write</span>(<span class="kw-2">&</span>[<span class="number">0</span>; <span class="number">1024</span>]).<span class="ident">unwrap</span>(), <span class="number">1024</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">s</span>.<span class="ident">by_ref</span>().<span class="ident">write</span>(<span class="kw-2">&</span>[<span class="number">0</span>; <span class="number">1024</span>]).<span class="ident">unwrap</span>(), <span class="number">1024</span>);
}
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="kw">fn</span> <span class="ident">empty_reads</span>() {
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">e</span> <span class="op">=</span> <span class="ident">empty</span>();
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">e</span>.<span class="ident">read</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> []).<span class="ident">unwrap</span>(), <span class="number">0</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">e</span>.<span class="ident">read</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> [<span class="number">0</span>]).<span class="ident">unwrap</span>(), <span class="number">0</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">e</span>.<span class="ident">read</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> [<span class="number">0</span>; <span class="number">1024</span>]).<span class="ident">unwrap</span>(), <span class="number">0</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">e</span>.<span class="ident">by_ref</span>().<span class="ident">read</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> [<span class="number">0</span>; <span class="number">1024</span>]).<span class="ident">unwrap</span>(), <span class="number">0</span>);
}
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="kw">fn</span> <span class="ident">repeat_repeats</span>() {
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">r</span> <span class="op">=</span> <span class="ident">repeat</span>(<span class="number">4</span>);
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">b</span> <span class="op">=</span> [<span class="number">0</span>; <span class="number">1024</span>];
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">r</span>.<span class="ident">read</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">b</span>).<span class="ident">unwrap</span>(), <span class="number">1024</span>);
<span class="macro">assert</span><span class="macro">!</span>(<span class="ident">b</span>.<span class="ident">iter</span>().<span class="ident">all</span>(<span class="op">|</span><span class="ident">b</span><span class="op">|</span> <span class="kw-2">*</span><span class="ident">b</span> <span class="op">==</span> <span class="number">4</span>));
}
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="kw">fn</span> <span class="ident">take_some_bytes</span>() {
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">repeat</span>(<span class="number">4</span>).<span class="ident">take</span>(<span class="number">100</span>).<span class="ident">bytes</span>().<span class="ident">count</span>(), <span class="number">100</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">repeat</span>(<span class="number">4</span>).<span class="ident">take</span>(<span class="number">100</span>).<span class="ident">bytes</span>().<span class="ident">next</span>().<span class="ident">unwrap</span>().<span class="ident">unwrap</span>(), <span class="number">4</span>);
<span class="macro">assert_eq</span><span class="macro">!</span>(<span class="ident">repeat</span>(<span class="number">1</span>).<span class="ident">take</span>(<span class="number">10</span>).<span class="ident">chain</span>(<span class="ident">repeat</span>(<span class="number">2</span>).<span class="ident">take</span>(<span class="number">10</span>)).<span class="ident">bytes</span>().<span class="ident">count</span>(), <span class="number">20</span>);
}
}
</pre>
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