Use futures::future::select instead of tokio::select!

Pros: less macros, fixes the missing feature issue.
Cons: a bit more code because `fututres` is an annoying crate
      which does not use `either::Either` and provides its
      own `Either` which does not have `map_either`, or
      basically anything for that matter.

crates/teloxide-core/Cargo.toml

@@ -31,7 +31,7 @@ native-tls = ["reqwest/native-tls"]
 nightly = []
 
 # Throttling bot adaptor
-throttle = ["vecrem", "tokio/macros"]
+throttle = ["vecrem"]
 
 # Trace bot adaptor
 trace_adaptor = []

crates/teloxide-core/src/adaptors/throttle/worker.rs

@@ -1,8 +1,11 @@
 use std::{
     collections::{hash_map::Entry, HashMap, VecDeque},
+    pin::pin,
     time::{Duration, Instant},
 };
 
+use either::Either;
+use futures::{future, FutureExt as _};
 use tokio::sync::{mpsc, mpsc::error::TryRecvError, oneshot::Sender};
 use vecrem::VecExt;
 
@@ -129,17 +132,19 @@ pub(super) async fn worker<B>(
         answer_info(&mut info_rx, &mut limits);
 
         loop {
-            tokio::select! {
-                freeze_until = freeze_rx.recv() => {
-                    freeze(
-                        &mut freeze_rx,
-                        slow_mode.as_mut(),
-                        &bot,
-                        freeze_until
+            let res = future::select(
+                pin!(freeze_rx.recv()),
+                pin!(read_from_rx(&mut rx, &mut queue, &mut rx_is_closed)),
             )
-                    .await;
-                },
-                () = read_from_rx(&mut rx, &mut queue, &mut rx_is_closed) => break,
+            .map(either)
+            .await
+            .map_either(|l| l.0, |r| r.0);
+
+            match res {
+                Either::Left(freeze_until) => {
+                    freeze(&mut freeze_rx, slow_mode.as_mut(), &bot, freeze_until).await;
+                }
+                Either::Right(()) => break,
             }
         }
         //debug_assert_eq!(queue.capacity(), limits.messages_per_sec_overall as usize);
@@ -372,6 +377,13 @@ async fn read_from_rx<T>(rx: &mut mpsc::Receiver<T>, queue: &mut Vec<T>, rx_is_c
     }
 }
 
+fn either<L, R>(x: future::Either<L, R>) -> Either<L, R> {
+    match x {
+        future::Either::Left(l) => Either::Left(l),
+        future::Either::Right(r) => Either::Right(r),
+    }
+}
+
 #[cfg(test)]
 mod tests {
     #[tokio::test]

crates/teloxide/Cargo.toml

@@ -94,6 +94,7 @@ futures = "0.3.15"
 pin-project = "1.0"
 serde_with_macros = "1.4"
 aquamarine = "0.1.11"
+either = "1.9.0"
 
 sqlx = { version = "0.6", optional = true, default-features = false, features = [
         "macros",

crates/teloxide/src/dispatching/dispatcher.rs

@@ -10,7 +10,12 @@ use crate::{
 };
 
 use dptree::di::{DependencyMap, DependencySupplier};
-use futures::{future::BoxFuture, stream::FuturesUnordered, StreamExt};
+use either::Either;
+use futures::{
+    future::{self, BoxFuture},
+    stream::FuturesUnordered,
+    FutureExt as _, StreamExt as _,
+};
 use tokio_stream::wrappers::ReceiverStream;
 
 use std::{
@@ -19,6 +24,7 @@ use std::{
     future::Future,
     hash::Hash,
     ops::{ControlFlow, Deref},
+    pin::pin,
     sync::{
         atomic::{AtomicBool, AtomicU32, Ordering},
         Arc,
@@ -321,12 +327,18 @@ where
             loop {
                 self.remove_inactive_workers_if_needed().await;
 
-                tokio::select! {
-                    upd = stream.next() => match upd {
-                        None => break,
+                let res = future::select(stream.next(), pin!(self.state.wait_for_changes()))
+                    .map(either)
+                    .await
+                    .map_either(|l| l.0, |r| r.0);
+
+                match res {
+                    Either::Left(upd) => match upd {
                         Some(upd) => self.process_update(upd, &update_listener_error_handler).await,
+                        None => break,
                     },
-                    () = self.state.wait_for_changes() => if self.state.is_shutting_down() {
+                    Either::Right(()) => {
+                        if self.state.is_shutting_down() {
                             if let Some(token) = stop_token.take() {
                                 log::debug!("Start shutting down dispatching...");
                                 token.stop();
@@ -335,6 +347,7 @@ where
                     }
                 }
             }
+        }
 
         self.workers
             .drain()
@@ -578,6 +591,12 @@ async fn handle_update<Err>(
     }
 }
 
+fn either<L, R>(x: future::Either<L, R>) -> Either<L, R> {
+    match x {
+        future::Either::Left(l) => Either::Left(l),
+        future::Either::Right(r) => Either::Right(r),
+    }
+}
 #[cfg(test)]
 mod tests {
     use std::convert::Infallible;