Exercise: ROT13

In this example, you will implement the classic "ROT13" cipher. Copy this code to the playground, and implement the missing bits. Only rotate ASCII alphabetic characters, to ensure the result is still valid UTF-8.

# // Copyright 2023 Google LLC
# // SPDX-License-Identifier: Apache-2.0
#
{{#include exercise.rs:head }}

// Implement the `Read` trait for `RotDecoder`.

{{#include exercise.rs:tests }}

What happens if you chain two RotDecoder instances together, each rotating by 13 characters?