How to convert between bytes and an array of type `[T; N]`
The values in an N-element array of type `T` can be considered as
1. [A value of type `[T; N]`](../long_example3_1/index.html),
2. [N-consecutive values of type `T`](../long_example3_2/index.html), or
3. [An element of slice `[[T; N]]`](../long_example3_3/index.html).