1 The `Sized` trait was implemented explicitly.
3 Erroneous code example:
8 impl Sized for Foo {} // error!
11 The `Sized` trait is a special trait built-in to the compiler for types with a
12 constant size known at compile-time. This trait is automatically implemented
13 for types as needed by the compiler, and it is currently disallowed to
14 explicitly implement it for a type.