Add embedded std

[lmbollen]

Rust's orphan rules prevent us from deriving traits like uDisplay, uDebug and uWrite from the ufmt package, effectively preventing us from formatting strings with existing types.

Therefore I propose to create an std like package that contains newtype wrappers for commonly used datatypes.
A first example is string.rs that uses String from heapless.

[DigitalBrains1]

I think this is a just written file, not a two year old file?

[lmbollen]

Ah yes, should have looke more carefully at the copyrights :)

[hydrolarus]

What types are the ones that cause you trouble? Because heapless has a feature flag ufmt that adds formatting to the types

https://github.com/rust-embedded/heapless/blob/f3aa0df15a5320fcc0849d0e2562d6e281cc0c8c/Cargo.toml#L33-L34

I see that we are using a different feature flag, ufmt-impl, I guess they changed the name in a newer version. So maybe we should update that too? We are using 0.7.x but there's a version 0.8.0 out.

[lmbollen]

What types are the ones that cause you trouble? Because heapless has a feature flag ufmt that adds formatting to the types

https://github.com/rust-embedded/heapless/blob/f3aa0df15a5320fcc0849d0e2562d6e281cc0c8c/Cargo.toml#L33-L34

I see that we are using a different feature flag, ufmt-impl, I guess they changed the name in a newer version. So maybe we should update that too? We are using 0.7.x but there's a version 0.8.0 out.

Oh nice! I'll take a look at those features and see if they cover my use cases :)
For now I'll turn this into a draft and I'll close it if it turns out unnecessary.

[lmbollen]

It turns out the ufmt feature of heapless does not implement uDisplay for their String, which is a desirable feature to me.

I did make a pull request for it on their repository

For now I propose we do continue adding this package. If we don't find any value for it besides this trait I'd like to remove it if heapless supports the feature in the future.

[lmbollen]

Lara pointed out we can just use the as_str() to print Strings.