Const

[greyblake]

Addresses #35

Changes

• Add const_fn attribute, which marks new / try_new and other underlying functions as const

Example

#[nutype(
    const_fn,
    validate(greater_or_equal = -1.0, less_or_equal = 1.0)
)]
struct Correlation(f32);

macro_rules! nutype_const {
    ($name:ident, $ty:ty, $value:expr) => {
        const $name: $ty = match <$ty>::try_new($value) {
            Ok(value) => value,
            Err(_) => panic!("Invalid value"),
        };
    };
}

nutype_const!(MAX_CORRELATION, Correlation, 1.0);

TODO

• const for into_inner() - double check with Add const getter for Copy types #126
  • Check if that will work for non Copy types
• Update docs
• Update README
• Update CHANGELOG
• Fix CI (if necessary)
• Code review