Move random utils to another trait.

embassy-traits/src/rng.rs

@@ -5,9 +5,9 @@ pub trait Rng {
     type Error;
 
     #[rustfmt::skip]
-    type RngFuture<'a>: Future<Output = Result<(), Self::Error>> + 'a
+    type RngFuture<'a>: Future<Output = Result<(), Self::Error> > + 'a
     where
-        Self: 'a;
+    Self: 'a;
 
     /// Completely fill the provided buffer with random bytes.
     ///
@@ -15,9 +15,11 @@ pub trait Rng {
     /// filling the buffer. Upon completion, the buffer will be completely
     /// filled or an error will have been reported.
     fn fill_bytes<'a>(&'a mut self, dest: &'a mut [u8]) -> Self::RngFuture<'a>;
+}
 
+pub trait Random: Rng {
     #[rustfmt::skip]
-    type NextFuture<'a>: Future<Output = Result<u32, Self::Error>> + 'a
+    type NextFuture<'a>: Future<Output = Result<u32, <Self as Rng>::Error>> + 'a
     where
         Self: 'a;