Macro core_extensions::impl_transparent_newtype

macro_rules! impl_transparent_newtype {
    ($S:ty) => { ... };
}

Available on crate feature transparent_newtype only.

For implementing the TransparentNewtype trait, to cast between a field and Self.

Example

use core_extensions::{TransparentNewtype, TransparentNewtypeExt, impl_transparent_newtype};

use std::cmp::{Ordering, Ord, PartialOrd};

#[repr(transparent)]
#[derive(PartialEq, Eq)]
struct Reverse<T: ?Sized>(T);

unsafe impl<T: ?Sized> TransparentNewtype for Reverse<T> {
    type Inner = T;
     
    // The argument must be `Self`
    // (it could also be Reverse<T> in here, it's just easier to always write Self)
    impl_transparent_newtype!{Self}
}

/* PartialOrd an Ord impls for Reverse */

let mut list = vec![3, 13, 21, 5, 8, 34];
     
<[Reverse<u64>]>::from_inner_mut(&mut list).sort();

assert_eq!(list, vec![34, 21, 13, 8, 5, 3]);