Feature request: infallible "from" for custom fields with bits that are a multiple of 8

[whitevegagabriel]

If a custom field takes up, say, 48 bits, and each bit can be arbitrarily anything, then it should be able to infallibly be converted from a [u8; 6].

But the current generated code performs a fallible try_from(u64), which would require wrangling a series of bytes into a [u8; 8], and then converted to a u64.

[hchataing]

Can you provide more context for this request ?
Currently the rust generator only produces TryFrom implementations for the nearest scalar type; not TryFrom<[u8;N]>.

[whitevegagabriel]

For example, lets consider this field declaration:

custom_field Field : 48

Right now, I can initialize it like this:

Field::try_from(0_u64).unwrap();

However, something that is 48 bits long is exactly 6 bytes long.
That means that if I know which 6 bytes I want to initialize Field with, I first have to wrangle it into a u64, and then initialize Field in a way that may fail if I wrangle my bytes into a u64 incorrectly`.

If Field were to implement From<[u8; 6]>, then there are fewer things that could go wrong in my conversion. (ignoring endianness, which complicates matters)

Let me know if I need to clarify further!