Rollup merge of #59221 - czipperz:as_ref_documentation, r=Centril

Option and Result: Add references to documentation of as_ref and as_mut

This makes the documentation more consistent with that of `Pin::as_ref` which converts "from `&Pin<Pointer<T>>` to `Pin<&t>`".

This generally makes it clearer that the reference is going inside the option.

src/libcore/option.rs

@@ -210,7 +210,7 @@ pub fn is_none(&self) -> bool {
     // Adapter for working with references
     /////////////////////////////////////////////////////////////////////////
 
-    /// Converts from `Option<T>` to `Option<&T>`.
+    /// Converts from `&Option<T>` to `Option<&T>`.
     ///
     /// # Examples
     ///
@@ -239,7 +239,7 @@ pub fn as_ref(&self) -> Option<&T> {
         }
     }
 
-    /// Converts from `Option<T>` to `Option<&mut T>`.
+    /// Converts from `&mut Option<T>` to `Option<&mut T>`.
     ///
     /// # Examples
     ///

src/libcore/result.rs

@@ -369,7 +369,7 @@ pub fn err(self) -> Option<E> {
     // Adapter for working with references
     /////////////////////////////////////////////////////////////////////////
 
-    /// Converts from `Result<T, E>` to `Result<&T, &E>`.
+    /// Converts from `&Result<T, E>` to `Result<&T, &E>`.
     ///
     /// Produces a new `Result`, containing a reference
     /// into the original, leaving the original in place.
@@ -394,7 +394,7 @@ pub fn as_ref(&self) -> Result<&T, &E> {
         }
     }
 
-    /// Converts from `Result<T, E>` to `Result<&mut T, &mut E>`.
+    /// Converts from `&mut Result<T, E>` to `Result<&mut T, &mut E>`.
     ///
     /// # Examples
     ///