1//! Combinators and utilities for working with `Future`s, `Stream`s, `Sink`s,
2//! and the `AsyncRead` and `AsyncWrite` traits.
3
4#![cfg_attr(feature = "write-all-vectored", feature(io_slice_advance))]
5#![cfg_attr(not(feature = "std"), no_std)]
6#![warn(
7 missing_debug_implementations,
8 missing_docs,
9 rust_2018_idioms,
10 single_use_lifetimes,
11 unreachable_pub
12)]
13#![doc(test(
14 no_crate_inject,
15 attr(
16 deny(warnings, rust_2018_idioms, single_use_lifetimes),
17 allow(dead_code, unused_assignments, unused_variables)
18 )
19))]
20#![cfg_attr(docsrs, feature(doc_cfg))]
21
22#[cfg(all(feature = "bilock", not(feature = "unstable")))]
23compile_error!("The `bilock` feature requires the `unstable` feature as an explicit opt-in to unstable features");
24
25#[cfg(feature = "alloc")]
26extern crate alloc;
27
28// Macro re-exports
29pub use futures_core::ready;
30pub use pin_utils::pin_mut;
31
32#[cfg(feature = "async-await")]
33#[macro_use]
34mod async_await;
35#[cfg(feature = "async-await")]
36#[doc(hidden)]
37pub use self::async_await::*;
38
39// Not public API.
40#[cfg(feature = "async-await")]
41#[doc(hidden)]
42pub mod __private {
43 pub use crate::*;
44 pub use core::{
45 option::Option::{self, None, Some},
46 pin::Pin,
47 result::Result::{Err, Ok},
48 };
49
50 pub mod async_await {
51 pub use crate::async_await::*;
52 }
53}
54
55#[cfg(feature = "sink")]
56macro_rules! delegate_sink {
57 ($field:ident, $item:ty) => {
58 fn poll_ready(
59 self: core::pin::Pin<&mut Self>,
60 cx: &mut core::task::Context<'_>,
61 ) -> core::task::Poll<Result<(), Self::Error>> {
62 self.project().$field.poll_ready(cx)
63 }
64
65 fn start_send(self: core::pin::Pin<&mut Self>, item: $item) -> Result<(), Self::Error> {
66 self.project().$field.start_send(item)
67 }
68
69 fn poll_flush(
70 self: core::pin::Pin<&mut Self>,
71 cx: &mut core::task::Context<'_>,
72 ) -> core::task::Poll<Result<(), Self::Error>> {
73 self.project().$field.poll_flush(cx)
74 }
75
76 fn poll_close(
77 self: core::pin::Pin<&mut Self>,
78 cx: &mut core::task::Context<'_>,
79 ) -> core::task::Poll<Result<(), Self::Error>> {
80 self.project().$field.poll_close(cx)
81 }
82 };
83}
84
85macro_rules! delegate_future {
86 ($field:ident) => {
87 fn poll(
88 self: core::pin::Pin<&mut Self>,
89 cx: &mut core::task::Context<'_>,
90 ) -> core::task::Poll<Self::Output> {
91 self.project().$field.poll(cx)
92 }
93 };
94}
95
96macro_rules! delegate_stream {
97 ($field:ident) => {
98 fn poll_next(
99 self: core::pin::Pin<&mut Self>,
100 cx: &mut core::task::Context<'_>,
101 ) -> core::task::Poll<Option<Self::Item>> {
102 self.project().$field.poll_next(cx)
103 }
104 fn size_hint(&self) -> (usize, Option<usize>) {
105 self.$field.size_hint()
106 }
107 };
108}
109
110#[cfg(feature = "io")]
111#[cfg(feature = "std")]
112macro_rules! delegate_async_write {
113 ($field:ident) => {
114 fn poll_write(
115 self: core::pin::Pin<&mut Self>,
116 cx: &mut core::task::Context<'_>,
117 buf: &[u8],
118 ) -> core::task::Poll<std::io::Result<usize>> {
119 self.project().$field.poll_write(cx, buf)
120 }
121 fn poll_write_vectored(
122 self: core::pin::Pin<&mut Self>,
123 cx: &mut core::task::Context<'_>,
124 bufs: &[std::io::IoSlice<'_>],
125 ) -> core::task::Poll<std::io::Result<usize>> {
126 self.project().$field.poll_write_vectored(cx, bufs)
127 }
128 fn poll_flush(
129 self: core::pin::Pin<&mut Self>,
130 cx: &mut core::task::Context<'_>,
131 ) -> core::task::Poll<std::io::Result<()>> {
132 self.project().$field.poll_flush(cx)
133 }
134 fn poll_close(
135 self: core::pin::Pin<&mut Self>,
136 cx: &mut core::task::Context<'_>,
137 ) -> core::task::Poll<std::io::Result<()>> {
138 self.project().$field.poll_close(cx)
139 }
140 };
141}
142
143#[cfg(feature = "io")]
144#[cfg(feature = "std")]
145macro_rules! delegate_async_read {
146 ($field:ident) => {
147 fn poll_read(
148 self: core::pin::Pin<&mut Self>,
149 cx: &mut core::task::Context<'_>,
150 buf: &mut [u8],
151 ) -> core::task::Poll<std::io::Result<usize>> {
152 self.project().$field.poll_read(cx, buf)
153 }
154
155 fn poll_read_vectored(
156 self: core::pin::Pin<&mut Self>,
157 cx: &mut core::task::Context<'_>,
158 bufs: &mut [std::io::IoSliceMut<'_>],
159 ) -> core::task::Poll<std::io::Result<usize>> {
160 self.project().$field.poll_read_vectored(cx, bufs)
161 }
162 };
163}
164
165#[cfg(feature = "io")]
166#[cfg(feature = "std")]
167macro_rules! delegate_async_buf_read {
168 ($field:ident) => {
169 fn poll_fill_buf(
170 self: core::pin::Pin<&mut Self>,
171 cx: &mut core::task::Context<'_>,
172 ) -> core::task::Poll<std::io::Result<&[u8]>> {
173 self.project().$field.poll_fill_buf(cx)
174 }
175
176 fn consume(self: core::pin::Pin<&mut Self>, amt: usize) {
177 self.project().$field.consume(amt)
178 }
179 };
180}
181
182macro_rules! delegate_access_inner {
183 ($field:ident, $inner:ty, ($($ind:tt)*)) => {
184 /// Acquires a reference to the underlying sink or stream that this combinator is
185 /// pulling from.
186 pub fn get_ref(&self) -> &$inner {
187 (&self.$field) $($ind get_ref())*
188 }
189
190 /// Acquires a mutable reference to the underlying sink or stream that this
191 /// combinator is pulling from.
192 ///
193 /// Note that care must be taken to avoid tampering with the state of the
194 /// sink or stream which may otherwise confuse this combinator.
195 pub fn get_mut(&mut self) -> &mut $inner {
196 (&mut self.$field) $($ind get_mut())*
197 }
198
199 /// Acquires a pinned mutable reference to the underlying sink or stream that this
200 /// combinator is pulling from.
201 ///
202 /// Note that care must be taken to avoid tampering with the state of the
203 /// sink or stream which may otherwise confuse this combinator.
204 pub fn get_pin_mut(self: core::pin::Pin<&mut Self>) -> core::pin::Pin<&mut $inner> {
205 self.project().$field $($ind get_pin_mut())*
206 }
207
208 /// Consumes this combinator, returning the underlying sink or stream.
209 ///
210 /// Note that this may discard intermediate state of this combinator, so
211 /// care should be taken to avoid losing resources when this is called.
212 pub fn into_inner(self) -> $inner {
213 self.$field $($ind into_inner())*
214 }
215 }
216}
217
218macro_rules! delegate_all {
219 (@trait Future $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
220 impl<$($arg),*> futures_core::future::Future for $name<$($arg),*> where $t: futures_core::future::Future $(, $($bound)*)* {
221 type Output = <$t as futures_core::future::Future>::Output;
222
223 delegate_future!(inner);
224 }
225 };
226 (@trait FusedFuture $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
227 impl<$($arg),*> futures_core::future::FusedFuture for $name<$($arg),*> where $t: futures_core::future::FusedFuture $(, $($bound)*)* {
228 fn is_terminated(&self) -> bool {
229 self.inner.is_terminated()
230 }
231 }
232 };
233 (@trait Stream $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
234 impl<$($arg),*> futures_core::stream::Stream for $name<$($arg),*> where $t: futures_core::stream::Stream $(, $($bound)*)* {
235 type Item = <$t as futures_core::stream::Stream>::Item;
236
237 delegate_stream!(inner);
238 }
239 };
240 (@trait FusedStream $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
241 impl<$($arg),*> futures_core::stream::FusedStream for $name<$($arg),*> where $t: futures_core::stream::FusedStream $(, $($bound)*)* {
242 fn is_terminated(&self) -> bool {
243 self.inner.is_terminated()
244 }
245 }
246 };
247 (@trait Sink $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
248 #[cfg(feature = "sink")]
249 impl<_Item, $($arg),*> futures_sink::Sink<_Item> for $name<$($arg),*> where $t: futures_sink::Sink<_Item> $(, $($bound)*)* {
250 type Error = <$t as futures_sink::Sink<_Item>>::Error;
251
252 delegate_sink!(inner, _Item);
253 }
254 };
255 (@trait Debug $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
256 impl<$($arg),*> core::fmt::Debug for $name<$($arg),*> where $t: core::fmt::Debug $(, $($bound)*)* {
257 fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
258 core::fmt::Debug::fmt(&self.inner, f)
259 }
260 }
261 };
262 (@trait AccessInner[$inner:ty, ($($ind:tt)*)] $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
263 impl<$($arg),*> $name<$($arg),*> $(where $($bound)*)* {
264 delegate_access_inner!(inner, $inner, ($($ind)*));
265 }
266 };
267 (@trait New[|$($param:ident: $paramt:ty),*| $cons:expr] $name:ident < $($arg:ident),* > ($t:ty) $(where $($bound:tt)*)*) => {
268 impl<$($arg),*> $name<$($arg),*> $(where $($bound)*)* {
269 pub(crate) fn new($($param: $paramt),*) -> Self {
270 Self { inner: $cons }
271 }
272 }
273 };
274 ($(#[$attr:meta])* $name:ident<$($arg:ident),*>($t:ty) : $ftrait:ident $([$($targs:tt)*])* $({$($item:tt)*})* $(where $($bound:tt)*)*) => {
275 pin_project_lite::pin_project! {
276 #[must_use = "futures/streams/sinks do nothing unless you `.await` or poll them"]
277 $(#[$attr])*
278 pub struct $name< $($arg),* > $(where $($bound)*)* { #[pin] inner: $t }
279 }
280
281 impl<$($arg),*> $name< $($arg),* > $(where $($bound)*)* {
282 $($($item)*)*
283 }
284
285 delegate_all!(@trait $ftrait $([$($targs)*])* $name<$($arg),*>($t) $(where $($bound)*)*);
286 };
287 ($(#[$attr:meta])* $name:ident<$($arg:ident),*>($t:ty) : $ftrait:ident $([$($ftargs:tt)*])* + $strait:ident $([$($stargs:tt)*])* $(+ $trait:ident $([$($targs:tt)*])*)* $({$($item:tt)*})* $(where $($bound:tt)*)*) => {
288 delegate_all!($(#[$attr])* $name<$($arg),*>($t) : $strait $([$($stargs)*])* $(+ $trait $([$($targs)*])*)* $({$($item)*})* $(where $($bound)*)*);
289
290 delegate_all!(@trait $ftrait $([$($ftargs)*])* $name<$($arg),*>($t) $(where $($bound)*)*);
291 };
292}
293
294pub mod future;
295#[doc(no_inline)]
296pub use crate::future::{Future, FutureExt, TryFuture, TryFutureExt};
297
298pub mod stream;
299#[doc(no_inline)]
300pub use crate::stream::{Stream, StreamExt, TryStream, TryStreamExt};
301
302#[cfg(feature = "sink")]
303#[cfg_attr(docsrs, doc(cfg(feature = "sink")))]
304pub mod sink;
305#[cfg(feature = "sink")]
306#[doc(no_inline)]
307pub use crate::sink::{Sink, SinkExt};
308
309pub mod task;
310
311pub mod never;
312
313#[cfg(feature = "compat")]
314#[cfg_attr(docsrs, doc(cfg(feature = "compat")))]
315pub mod compat;
316
317#[cfg(feature = "io")]
318#[cfg_attr(docsrs, doc(cfg(feature = "io")))]
319#[cfg(feature = "std")]
320pub mod io;
321#[cfg(feature = "io")]
322#[cfg(feature = "std")]
323#[doc(no_inline)]
324pub use crate::io::{
325 AsyncBufRead, AsyncBufReadExt, AsyncRead, AsyncReadExt, AsyncSeek, AsyncSeekExt, AsyncWrite,
326 AsyncWriteExt,
327};
328
329#[cfg(feature = "alloc")]
330pub mod lock;
331
332#[cfg(not(futures_no_atomic_cas))]
333#[cfg(feature = "alloc")]
334mod abortable;
335
336mod fns;
337mod unfold_state;
338