MonadFailAnyExt

src/func.rs

@@ -300,12 +300,29 @@ pub trait MonadFailAny {
         Self: 'a,
     {
         <Self::W<Result<E1, E0>> as Monad>::bind(Self::map_err(wa, Err), |fa| match fa {
-            Ok(a) => <Self::W<Result<E1, E0>> as Pure>::pure(a),
-            Err(e) => <Self::W<Result<E1, E0>> as Fail<Result<E1, E0>>>::fail(Ok(e)),
+            Ok(a) => Self::pure(a),
+            Err(e) => Self::fail(Ok(e)),
         })
     }
 }
 
+pub trait MonadFailAnyExt: MonadFailAny {
+    fn pure<'a, E: 'a, A: 'a>(a: A) -> <Self::W<E> as WeakFunctor>::F<'a, A>
+    where
+        Self: 'a,
+    {
+        <Self::W<E> as Pure>::pure(a)
+    }
+    fn fail<'a, E: 'a, A: 'a>(e: E) -> <Self::W<E> as WeakFunctor>::F<'a, A>
+    where
+        Self: 'a,
+    {
+        <Self::W<E> as Fail<E>>::fail(e)
+    }
+}
+
+impl<Fallible: ?Sized + MonadFailAny> MonadFailAnyExt for Fallible {}
+
 /// Represents a (collection of) [Monad]\(s),
 /// wrapped values of which are interchangeable with another [Monad]'s
 /// wrapped [Result]s.