rand_core: Rename CryptoRngCore::upcast to as_rngcore

Author: vks

rand_chacha/src/chacha.rs

@@ -630,7 +630,7 @@ mod test {
 
         let rng = &mut ChaChaRng::from_seed(Default::default()) as &mut dyn CryptoRngCore;
         let r1 = rng.next_u64();
-        let rng: &mut dyn RngCore = rng.upcast();
+        let rng: &mut dyn RngCore = rng.as_rngcore();
         let r2 = rng.next_u64();
         assert_ne!(r1, r2);
     }

rand_core/src/lib.rs

@@ -210,14 +210,14 @@ pub trait CryptoRng {}
 
 /// An extension trait to support trait objects that implement [`RngCore`] and
 /// [`CryptoRng`]. Upcasting to [`RngCore`] is supported via the
-/// [`CryptoRngCore::upcast`] method.
+/// [`CryptoRngCore::as_rngcore`] method.
 pub trait CryptoRngCore: RngCore {
     /// Upcast to an [`RngCore`] trait object.
-    fn upcast(&mut self) -> &mut dyn RngCore;
+    fn as_rngcore(&mut self) -> &mut dyn RngCore;
 }
 
 impl<T: CryptoRng + RngCore> CryptoRngCore for T {
-    fn upcast(&mut self) -> &mut dyn RngCore {
+    fn as_rngcore(&mut self) -> &mut dyn RngCore {
         self
     }
 }