| <!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/futures-util-0.3.28/src/sink/with.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>with.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../../normalize.css"><link rel="stylesheet" href="../../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../../ayu.css" disabled><link rel="stylesheet" href="../../../dark.css" disabled><link rel="stylesheet" href="../../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../../storage.js"></script><script defer src="../../../source-script.js"></script><script defer src="../../../source-files.js"></script><script defer src="../../../main.js"></script><noscript><link rel="stylesheet" href="../../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../../futures_util/index.html"><div class="logo-container"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../../futures_util/index.html"><img class="rust-logo" src="../../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="kw">use </span>core::fmt; |
| <span class="kw">use </span>core::marker::PhantomData; |
| <span class="kw">use </span>core::pin::Pin; |
| <span class="kw">use </span>futures_core::future::Future; |
| <span class="kw">use </span>futures_core::ready; |
| <span class="kw">use </span>futures_core::stream::Stream; |
| <span class="kw">use </span>futures_core::task::{Context, Poll}; |
| <span class="kw">use </span>futures_sink::Sink; |
| <span class="kw">use </span>pin_project_lite::pin_project; |
| |
| <span class="macro">pin_project! </span>{ |
| <span class="doccomment">/// Sink for the [`with`](super::SinkExt::with) method. |
| </span><span class="attribute">#[must_use = <span class="string">"sinks do nothing unless polled"</span>] |
| </span><span class="kw">pub struct </span>With<Si, Item, U, Fut, F> { |
| <span class="attribute">#[pin] |
| </span>sink: Si, |
| f: F, |
| <span class="attribute">#[pin] |
| </span>state: <span class="prelude-ty">Option</span><Fut>, |
| _phantom: PhantomData<<span class="kw">fn</span>(U) -> Item>, |
| } |
| } |
| |
| <span class="kw">impl</span><Si, Item, U, Fut, F> fmt::Debug <span class="kw">for </span>With<Si, Item, U, Fut, F> |
| <span class="kw">where |
| </span>Si: fmt::Debug, |
| Fut: fmt::Debug, |
| { |
| <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, f: <span class="kw-2">&mut </span>fmt::Formatter<<span class="lifetime">'_</span>>) -> fmt::Result { |
| f.debug_struct(<span class="string">"With"</span>).field(<span class="string">"sink"</span>, <span class="kw-2">&</span><span class="self">self</span>.sink).field(<span class="string">"state"</span>, <span class="kw-2">&</span><span class="self">self</span>.state).finish() |
| } |
| } |
| |
| <span class="kw">impl</span><Si, Item, U, Fut, F> With<Si, Item, U, Fut, F> |
| <span class="kw">where |
| </span>Si: Sink<Item>, |
| F: FnMut(U) -> Fut, |
| Fut: Future, |
| { |
| <span class="kw">pub</span>(<span class="kw">super</span>) <span class="kw">fn </span>new<E>(sink: Si, f: F) -> <span class="self">Self |
| </span><span class="kw">where |
| </span>Fut: Future<Output = <span class="prelude-ty">Result</span><Item, E>>, |
| E: From<Si::Error>, |
| { |
| <span class="self">Self </span>{ state: <span class="prelude-val">None</span>, sink, f, _phantom: PhantomData } |
| } |
| } |
| |
| <span class="kw">impl</span><Si, Item, U, Fut, F> Clone <span class="kw">for </span>With<Si, Item, U, Fut, F> |
| <span class="kw">where |
| </span>Si: Clone, |
| F: Clone, |
| Fut: Clone, |
| { |
| <span class="kw">fn </span>clone(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="self">Self </span>{ |
| <span class="self">Self </span>{ |
| state: <span class="self">self</span>.state.clone(), |
| sink: <span class="self">self</span>.sink.clone(), |
| f: <span class="self">self</span>.f.clone(), |
| _phantom: PhantomData, |
| } |
| } |
| } |
| |
| <span class="comment">// Forwarding impl of Stream from the underlying sink |
| </span><span class="kw">impl</span><S, Item, U, Fut, F> Stream <span class="kw">for </span>With<S, Item, U, Fut, F> |
| <span class="kw">where |
| </span>S: Stream + Sink<Item>, |
| F: FnMut(U) -> Fut, |
| Fut: Future, |
| { |
| <span class="kw">type </span>Item = S::Item; |
| |
| <span class="macro">delegate_stream!</span>(sink); |
| } |
| |
| <span class="kw">impl</span><Si, Item, U, Fut, F, E> With<Si, Item, U, Fut, F> |
| <span class="kw">where |
| </span>Si: Sink<Item>, |
| F: FnMut(U) -> Fut, |
| Fut: Future<Output = <span class="prelude-ty">Result</span><Item, E>>, |
| E: From<Si::Error>, |
| { |
| <span class="macro">delegate_access_inner!</span>(sink, Si, ()); |
| |
| <span class="doccomment">/// Completes the processing of previous item if any. |
| </span><span class="kw">fn </span>poll(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>) -> Poll<<span class="prelude-ty">Result</span><(), E>> { |
| <span class="kw">let </span><span class="kw-2">mut </span>this = <span class="self">self</span>.project(); |
| |
| <span class="kw">let </span>item = <span class="kw">match </span>this.state.as_mut().as_pin_mut() { |
| <span class="prelude-val">None </span>=> <span class="kw">return </span>Poll::Ready(<span class="prelude-val">Ok</span>(())), |
| <span class="prelude-val">Some</span>(fut) => <span class="macro">ready!</span>(fut.poll(cx))<span class="question-mark">?</span>, |
| }; |
| this.state.set(<span class="prelude-val">None</span>); |
| this.sink.start_send(item)<span class="question-mark">?</span>; |
| Poll::Ready(<span class="prelude-val">Ok</span>(())) |
| } |
| } |
| |
| <span class="kw">impl</span><Si, Item, U, Fut, F, E> Sink<U> <span class="kw">for </span>With<Si, Item, U, Fut, F> |
| <span class="kw">where |
| </span>Si: Sink<Item>, |
| F: FnMut(U) -> Fut, |
| Fut: Future<Output = <span class="prelude-ty">Result</span><Item, E>>, |
| E: From<Si::Error>, |
| { |
| <span class="kw">type </span>Error = E; |
| |
| <span class="kw">fn </span>poll_ready(<span class="kw-2">mut </span><span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>) -> Poll<<span class="prelude-ty">Result</span><(), <span class="self">Self</span>::Error>> { |
| <span class="macro">ready!</span>(<span class="self">self</span>.as_mut().poll(cx))<span class="question-mark">?</span>; |
| <span class="macro">ready!</span>(<span class="self">self</span>.project().sink.poll_ready(cx)<span class="question-mark">?</span>); |
| Poll::Ready(<span class="prelude-val">Ok</span>(())) |
| } |
| |
| <span class="kw">fn </span>start_send(<span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, item: U) -> <span class="prelude-ty">Result</span><(), <span class="self">Self</span>::Error> { |
| <span class="kw">let </span><span class="kw-2">mut </span>this = <span class="self">self</span>.project(); |
| |
| <span class="macro">assert!</span>(this.state.is_none()); |
| this.state.set(<span class="prelude-val">Some</span>((this.f)(item))); |
| <span class="prelude-val">Ok</span>(()) |
| } |
| |
| <span class="kw">fn </span>poll_flush(<span class="kw-2">mut </span><span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>) -> Poll<<span class="prelude-ty">Result</span><(), <span class="self">Self</span>::Error>> { |
| <span class="macro">ready!</span>(<span class="self">self</span>.as_mut().poll(cx))<span class="question-mark">?</span>; |
| <span class="macro">ready!</span>(<span class="self">self</span>.project().sink.poll_flush(cx)<span class="question-mark">?</span>); |
| Poll::Ready(<span class="prelude-val">Ok</span>(())) |
| } |
| |
| <span class="kw">fn </span>poll_close(<span class="kw-2">mut </span><span class="self">self</span>: Pin<<span class="kw-2">&mut </span><span class="self">Self</span>>, cx: <span class="kw-2">&mut </span>Context<<span class="lifetime">'_</span>>) -> Poll<<span class="prelude-ty">Result</span><(), <span class="self">Self</span>::Error>> { |
| <span class="macro">ready!</span>(<span class="self">self</span>.as_mut().poll(cx))<span class="question-mark">?</span>; |
| <span class="macro">ready!</span>(<span class="self">self</span>.project().sink.poll_close(cx)<span class="question-mark">?</span>); |
| Poll::Ready(<span class="prelude-val">Ok</span>(())) |
| } |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../../" data-current-crate="futures_util" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
