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