| <!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-core-0.3.28/src/future.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>future.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_core/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_core/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="doccomment">//! Futures. |
| |
| </span><span class="kw">use </span>core::ops::DerefMut; |
| <span class="kw">use </span>core::pin::Pin; |
| <span class="kw">use </span>core::task::{Context, Poll}; |
| |
| <span class="attribute">#[doc(no_inline)] |
| </span><span class="kw">pub use </span>core::future::Future; |
| |
| <span class="doccomment">/// An owned dynamically typed [`Future`] for use in cases where you can't |
| /// statically type your result or need to add some indirection. |
| </span><span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] |
| </span><span class="kw">pub type </span>BoxFuture<<span class="lifetime">'a</span>, T> = Pin<alloc::boxed::Box<<span class="kw">dyn </span>Future<Output = T> + Send + <span class="lifetime">'a</span>>>; |
| |
| <span class="doccomment">/// `BoxFuture`, but without the `Send` requirement. |
| </span><span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] |
| </span><span class="kw">pub type </span>LocalBoxFuture<<span class="lifetime">'a</span>, T> = Pin<alloc::boxed::Box<<span class="kw">dyn </span>Future<Output = T> + <span class="lifetime">'a</span>>>; |
| |
| <span class="doccomment">/// A future which tracks whether or not the underlying future |
| /// should no longer be polled. |
| /// |
| /// `is_terminated` will return `true` if a future should no longer be polled. |
| /// Usually, this state occurs after `poll` (or `try_poll`) returned |
| /// `Poll::Ready`. However, `is_terminated` may also return `true` if a future |
| /// has become inactive and can no longer make progress and should be ignored |
| /// or dropped rather than being `poll`ed again. |
| </span><span class="kw">pub trait </span>FusedFuture: Future { |
| <span class="doccomment">/// Returns `true` if the underlying future should no longer be polled. |
| </span><span class="kw">fn </span>is_terminated(<span class="kw-2">&</span><span class="self">self</span>) -> bool; |
| } |
| |
| <span class="kw">impl</span><F: FusedFuture + <span class="question-mark">?</span>Sized + Unpin> FusedFuture <span class="kw">for </span><span class="kw-2">&mut </span>F { |
| <span class="kw">fn </span>is_terminated(<span class="kw-2">&</span><span class="self">self</span>) -> bool { |
| <F <span class="kw">as </span>FusedFuture>::is_terminated(<span class="kw-2">&**</span><span class="self">self</span>) |
| } |
| } |
| |
| <span class="kw">impl</span><P> FusedFuture <span class="kw">for </span>Pin<P> |
| <span class="kw">where |
| </span>P: DerefMut + Unpin, |
| P::Target: FusedFuture, |
| { |
| <span class="kw">fn </span>is_terminated(<span class="kw-2">&</span><span class="self">self</span>) -> bool { |
| <P::Target <span class="kw">as </span>FusedFuture>::is_terminated(<span class="kw-2">&**</span><span class="self">self</span>) |
| } |
| } |
| |
| <span class="kw">mod </span>private_try_future { |
| <span class="kw">use </span><span class="kw">super</span>::Future; |
| |
| <span class="kw">pub trait </span>Sealed {} |
| |
| <span class="kw">impl</span><F, T, E> Sealed <span class="kw">for </span>F <span class="kw">where </span>F: <span class="question-mark">?</span>Sized + Future<Output = <span class="prelude-ty">Result</span><T, E>> {} |
| } |
| |
| <span class="doccomment">/// A convenience for futures that return `Result` values that includes |
| /// a variety of adapters tailored to such futures. |
| </span><span class="kw">pub trait </span>TryFuture: Future + private_try_future::Sealed { |
| <span class="doccomment">/// The type of successful values yielded by this future |
| </span><span class="kw">type </span><span class="prelude-val">Ok</span>; |
| |
| <span class="doccomment">/// The type of failures yielded by this future |
| </span><span class="kw">type </span>Error; |
| |
| <span class="doccomment">/// Poll this `TryFuture` as if it were a `Future`. |
| /// |
| /// This method is a stopgap for a compiler limitation that prevents us from |
| /// directly inheriting from the `Future` trait; in the future it won't be |
| /// needed. |
| </span><span class="kw">fn </span>try_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><<span class="self">Self</span>::Ok, <span class="self">Self</span>::Error>>; |
| } |
| |
| <span class="kw">impl</span><F, T, E> TryFuture <span class="kw">for </span>F |
| <span class="kw">where |
| </span>F: <span class="question-mark">?</span>Sized + Future<Output = <span class="prelude-ty">Result</span><T, E>>, |
| { |
| <span class="kw">type </span><span class="prelude-val">Ok </span>= T; |
| <span class="kw">type </span>Error = E; |
| |
| <span class="attribute">#[inline] |
| </span><span class="kw">fn </span>try_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="self">Self</span>::Output> { |
| <span class="self">self</span>.poll(cx) |
| } |
| } |
| |
| <span class="attribute">#[cfg(feature = <span class="string">"alloc"</span>)] |
| </span><span class="kw">mod </span>if_alloc { |
| <span class="kw">use super</span>::<span class="kw-2">*</span>; |
| <span class="kw">use </span>alloc::boxed::Box; |
| |
| <span class="kw">impl</span><F: FusedFuture + <span class="question-mark">?</span>Sized + Unpin> FusedFuture <span class="kw">for </span>Box<F> { |
| <span class="kw">fn </span>is_terminated(<span class="kw-2">&</span><span class="self">self</span>) -> bool { |
| <F <span class="kw">as </span>FusedFuture>::is_terminated(<span class="kw-2">&**</span><span class="self">self</span>) |
| } |
| } |
| |
| <span class="attribute">#[cfg(feature = <span class="string">"std"</span>)] |
| </span><span class="kw">impl</span><F: FusedFuture> FusedFuture <span class="kw">for </span>std::panic::AssertUnwindSafe<F> { |
| <span class="kw">fn </span>is_terminated(<span class="kw-2">&</span><span class="self">self</span>) -> bool { |
| <F <span class="kw">as </span>FusedFuture>::is_terminated(<span class="kw-2">&**</span><span class="self">self</span>) |
| } |
| } |
| } |
| </code></pre></div> |
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