Added FromStream + Extend for BTreeMap

Author: sunjay

src/collections/btree_map/extend.rs

@@ -0,0 +1,16 @@
+use std::pin::Pin;
+use std::collections::BTreeMap;
+
+use crate::prelude::*;
+use crate::stream::{Extend, IntoStream};
+
+impl<K: Ord, V> Extend<(K, V)> for BTreeMap<K, V> {
+    fn stream_extend<'a, S: IntoStream<Item = (K, V)> + 'a>(
+        &'a mut self,
+        stream: S,
+    ) -> Pin<Box<dyn Future<Output = ()> + 'a>> {
+        Box::pin(stream.into_stream().for_each(move |(k, v)| {
+            self.insert(k, v);
+        }))
+    }
+}

src/collections/btree_map/from_stream.rs

@@ -0,0 +1,24 @@
+use std::pin::Pin;
+use std::collections::BTreeMap;
+
+use crate::stream::{Extend, FromStream, IntoStream};
+
+impl<K: Ord, V> FromStream<(K, V)> for BTreeMap<K, V> {
+    #[inline]
+    fn from_stream<'a, S: IntoStream<Item = (K, V)>>(
+        stream: S,
+    ) -> Pin<Box<dyn core::future::Future<Output = Self> + 'a>>
+    where
+        <S as IntoStream>::IntoStream: 'a,
+    {
+        let stream = stream.into_stream();
+
+        Box::pin(async move {
+            pin_utils::pin_mut!(stream);
+
+            let mut out = BTreeMap::new();
+            out.stream_extend(stream).await;
+            out
+        })
+    }
+}

src/collections/btree_map/mod.rs

@@ -0,0 +1,7 @@
+//! The Rust B-Tree Map
+
+mod extend;
+mod from_stream;
+
+#[doc(inline)]
+pub use std::collections::BTreeMap;

src/collections/mod.rs

@@ -3,6 +3,8 @@
 //! This library provides efficient implementations of the most common general purpose programming
 //! data structures.
 
-mod vec_deque;
+pub mod vec_deque;
+pub mod btree_map;
 
-pub use vec_deque::*;
+pub use vec_deque::VecDeque;
+pub use btree_map::BTreeMap;