properly recurse through references

Author: RalfJung

text/0000-constants-in-patterns.md

@@ -123,9 +123,10 @@ Most of the values of primitive Rust types have structural equality (integers, `
 When a constant `C` of type `T` is used as a pattern, we first check that `T: PartialEq`.
 Furthermore we require that the value of `C` *has (recursive) structural equality*, which is defined recursively as follows:
 
-- Integers, `bool` and `char` values, and references always have structural equality.
+- Integers as well as `bool` and `char` values always have structural equality.
 - Tuples, arrays, and slices have structural equality if all their fields/elements have structural equality.
   (In particular, `()` and `[]` always have structural equality.)
+- References have structural equality if the value they point to has structural equality.
 - A value of `struct` or `enum` type has structural equality if its `PartialEq` behaves exactly like the one generated by `derive(PartialEq)`,
   and all fields (for enums: of the active variant) have structural equality.
 - A raw pointer has structural equality if it was defined as a constant integer (and then cast/transmuted).