Is a generic newtype possible?

[atezet]

Is it possible to create a generic newtype with nutype? When I do, let's say:

use nutype::nutype;

#[nutype(validate(predicate = |v| !v.is_empty()))]
struct NonEmptyVec<T>(Vec<T>);

I get:

 --> src/main.rs:4:27
  |
4 | struct NonEmptyVec<T>(Vec<T>);
  |                           ^ not found in this scope
  |
help: you might be missing a type parameter
  |
4 | struct NonEmptyVec<T><T>(Vec<T>);
  |                   +++

[greyblake]

Hi @atezet

It's not possible at the moment.
But I have this in mind and want to make it possible in the future.

[atezet]

I already like using the library as-is a lot, but definitely looking forward to that! Thanks

[greyblake]

@atezet Btw, if you need only non empty vector, I recommend taking a look at nonempty: https://github.com/cloudhead/nonempty

[atezet]

Thanks for the suggestion! We tried that at first, and iirc it worked for the cases where we needed a vector, but we also need IndexMap and some others. Unfortunately nonempty only supports Vec, even though its name would suggest otherwise.

I also suggested just using nutype and fixing the type of the stored values, but my colleague went ahead and implemented a newtype wrapping a generic Iterator for now.

Would love to see this to be possible with nutype or nonempty.