add is_err() to TryFuture extension

add fold_default to Future tools extension

Signed-off-by: Jason Volk <jason@zemos.net>

src/core/utils/future/try_ext_ext.rs

@@ -1,5 +1,8 @@
 //! Extended external extensions to futures::TryFutureExt
 #![allow(clippy::type_complexity)]
+// is_ok() has to consume *self rather than borrow. This extension is for a
+// caller only ever caring about result status while discarding all contents.
+#![allow(clippy::wrong_self_convention)]
 
 use futures::{
 	future::{MapOkOrElse, UnwrapOrElse},
@@ -11,12 +14,10 @@ pub trait TryExtExt<T, E>
 where
 	Self: TryFuture<Ok = T, Error = E> + Send,
 {
-	/// Resolves to a bool for whether the TryFuture (Future of a Result)
+	fn is_err(self) -> MapOkOrElse<Self, impl FnOnce(Self::Ok) -> bool, impl FnOnce(Self::Error) -> bool>
-	/// resolved to Ok or Err.
+	where
-	///
+		Self: Sized;
-	/// is_ok() has to consume *self rather than borrow. The intent of this
+
-	/// extension is therefor for a caller only ever caring about result status
-	/// while discarding all contents.
 	#[allow(clippy::wrong_self_convention)]
 	fn is_ok(self) -> MapOkOrElse<Self, impl FnOnce(Self::Ok) -> bool, impl FnOnce(Self::Error) -> bool>
 	where
@@ -44,6 +45,14 @@ impl<T, E, Fut> TryExtExt<T, E> for Fut
 where
 	Fut: TryFuture<Ok = T, Error = E> + Send,
 {
+	#[inline]
+	fn is_err(self) -> MapOkOrElse<Self, impl FnOnce(Self::Ok) -> bool, impl FnOnce(Self::Error) -> bool>
+	where
+		Self: Sized,
+	{
+		self.map_ok_or(true, |_| false)
+	}
+
 	#[inline]
 	fn is_ok(self) -> MapOkOrElse<Self, impl FnOnce(Self::Ok) -> bool, impl FnOnce(Self::Error) -> bool>
 	where

src/core/utils/stream/tools.rs

@@ -32,6 +32,12 @@ where
 	fn counts_with_cap<const CAP: usize>(self) -> impl Future<Output = HashMap<Item, usize>> + Send
 	where
 		<Self as Stream>::Item: Eq + Hash;
+
+	fn fold_default<T, F, Fut>(self, f: F) -> impl Future<Output = T> + Send
+	where
+		F: Fn(T, Item) -> Fut + Send,
+		Fut: Future<Output = T> + Send,
+		T: Default + Send;
 }
 
 impl<Item, S> Tools<Item> for S
@@ -77,4 +83,14 @@ where
 			counts
 		})
 	}
+
+	#[inline]
+	fn fold_default<T, F, Fut>(self, f: F) -> impl Future<Output = T> + Send
+	where
+		F: Fn(T, Item) -> Fut + Send,
+		Fut: Future<Output = T> + Send,
+		T: Default + Send,
+	{
+		self.fold(T::default(), f)
+	}
 }