Nutype 0.4.2

Changes

• Support no_std ( the dependency needs to be declared as nutype = { default-features = false } )
• Support integration with arbitrary crate (see arbitrary feature).
  • Support Arbitrary for integer types
  • Support Arbitrary for float types
  • Support Arbitrary for string inner types
  • Support Arbitrary for any inner types
• Possibility to specify boundaries (greater, greater_or_equal, less, less_or_equal, len_char_min, len_char_max) with expressions or named constants.
• Add #[inline] attribute to trivial functions
• Improve error messages

Highlights

Here is an example of nutype and arbitrary playing together:

use nutype::nutype;
use arbtest::arbtest;
use arbitrary::Arbitrary;

#[nutype(
    derive(Arbitrary, AsRef),
    sanitize(trim),
    validate(
        not_empty,
        len_char_max = 100,
    ),
)]
pub struct Title(String);

fn main() {
    arbtest(|u| {
        // Generate an arbitrary valid Title
        let title = Title::arbitrary(u)?;

        // The inner string is guaranteed to be non-empty
        assert!(!title.as_ref().is_empty());

        // The inner string is guaranteed not to exceed 100 characters
        assert!(title.as_ref().chars().count() <= 100);
        Ok(())
    });
}

As you can see the derived implementation of Arbitrary respects the validation rules.
In the similar way Arbitrary can be derived for integer and float based types.

Links

• Blog post
• Discussion on Reddit