From 46ecb8fbcf01ca7925584b4497c992015b90e7b5 Mon Sep 17 00:00:00 2001
From: little-dude <corentinhenry@gmail.com>
Date: Thu, 1 Oct 2020 10:19:32 +0200
Subject: [PATCH] remove un-necessary pin projections

see: https://users.rust-lang.org/t/is-my-pin-projection-actually-safe/49449/7?u=little_dude
---
 rust/Cargo.lock                               |  1 -
 rust/xaynet-client/Cargo.toml                 |  1 -
 rust/xaynet-client/src/lib.rs                 |  2 --
 .../src/utils/concurrent_futures.rs           | 34 ++++++++++++-------
 rust/xaynet-client/src/utils/mod.rs           |  1 +
 5 files changed, 23 insertions(+), 16 deletions(-)
 create mode 100644 rust/xaynet-client/src/utils/mod.rs

diff --git a/rust/Cargo.lock b/rust/Cargo.lock
index 8fcee2e2d..cfd0fe7e4 100644
--- a/rust/Cargo.lock
+++ b/rust/Cargo.lock
@@ -2862,7 +2862,6 @@ dependencies = [
  "bytes",
  "derive_more",
  "futures",
- "pin-project",
  "reqwest",
  "serde 1.0.116",
  "sodiumoxide",
diff --git a/rust/xaynet-client/Cargo.toml b/rust/xaynet-client/Cargo.toml
index c9a456c71..aa594b609 100644
--- a/rust/xaynet-client/Cargo.toml
+++ b/rust/xaynet-client/Cargo.toml
@@ -21,7 +21,6 @@ tracing = "0.1.19"
 async-trait = "0.1.40"
 xaynet-core = { path = "../xaynet-core", version = "0.1.0" }
 reqwest = { version = "0.10.8", default-features = false }
-pin-project = "0.4.24"
 futures = "0.3.5"
 
 [dev-dependencies]
diff --git a/rust/xaynet-client/src/lib.rs b/rust/xaynet-client/src/lib.rs
index 2d66cb3bf..9037dad13 100644
--- a/rust/xaynet-client/src/lib.rs
+++ b/rust/xaynet-client/src/lib.rs
@@ -45,8 +45,6 @@ extern crate async_trait;
 extern crate serde;
 #[macro_use]
 extern crate tracing;
-#[macro_use]
-extern crate pin_project;
 
 use std::time::Duration;
 
diff --git a/rust/xaynet-client/src/utils/concurrent_futures.rs b/rust/xaynet-client/src/utils/concurrent_futures.rs
index c093c055f..fb4230fd5 100644
--- a/rust/xaynet-client/src/utils/concurrent_futures.rs
+++ b/rust/xaynet-client/src/utils/concurrent_futures.rs
@@ -1,30 +1,26 @@
+#![allow(dead_code)]
+
 use std::{
     collections::VecDeque,
     pin::Pin,
     task::{Context, Poll},
-    time::Duration,
 };
 
 use futures::{
-    stream::{FuturesUnordered, Stream, StreamExt},
+    stream::{FuturesUnordered, Stream},
     Future,
 };
-use tokio::{
-    task::{JoinError, JoinHandle},
-    time::delay_for,
-};
+use tokio::task::{JoinError, JoinHandle};
 
 /// `ConcurrentFutures` can keep a capped number of futures running concurrently, and yield their
 /// result as they finish. When the max number of concurrent futures is reached, new tasks are
 /// queued until some in-flight futures finish.
-#[pin_project]
 pub struct ConcurrentFutures<T>
 where
     T: Future + Send + 'static,
     T::Output: Send + 'static,
 {
     /// in-flight futures
-    #[pin]
     running: FuturesUnordered<JoinHandle<T::Output>>,
     /// buffered tasks
     pending: VecDeque<T>,
@@ -50,15 +46,22 @@ where
     }
 }
 
+impl<T> Unpin for ConcurrentFutures<T>
+where
+    T: Future + Send + 'static,
+    T::Output: Send + 'static,
+{
+}
+
 impl<T> Stream for ConcurrentFutures<T>
 where
     T: Future + Send + 'static,
     T::Output: Send + 'static,
 {
     type Item = Result<T::Output, JoinError>;
-    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context) -> Poll<Option<Self::Item>> {
-        let this = self.project();
-        while this.running.len() < *this.max_in_flight {
+    fn poll_next(self: Pin<&mut Self>, cx: &mut Context) -> Poll<Option<Self::Item>> {
+        let this = self.get_mut();
+        while this.running.len() < this.max_in_flight {
             if let Some(pending) = this.pending.pop_front() {
                 let handle = tokio::spawn(pending);
                 this.running.push(handle);
@@ -66,12 +69,19 @@ where
                 break;
             }
         }
-        this.running.poll_next(cx)
+        Pin::new(&mut this.running).poll_next(cx)
     }
 }
 
 #[cfg(test)]
 mod tests {
+    use std::time::Duration;
+
+    use futures::stream::StreamExt;
+    use tokio::time::delay_for;
+
+    use super::*;
+
     #[tokio::test]
     async fn test() {
         let mut stream =
diff --git a/rust/xaynet-client/src/utils/mod.rs b/rust/xaynet-client/src/utils/mod.rs
new file mode 100644
index 000000000..fe1779808
--- /dev/null
+++ b/rust/xaynet-client/src/utils/mod.rs
@@ -0,0 +1 @@
+pub(crate) mod concurrent_futures;