Clarify that blocks are rvalues
@@ -288,6 +288,9 @@ let x: i32 = { println!("Hello."); 5 };
assert_eq!(5, x);
```
+Blocks are always [rvalues](#lvalues-and-rvalues) and evaluate the last
+expression in rvalue context.
+
## Method-call expressions
A _method call_ consists of an expression followed by a single dot, an
