Macro newtype 

macro_rules! newtype {
    ($(#[$meta:meta])* $vis:vis $name:ident($inner:ty)) => { ... };
}

Declare a distinct newtype in one line — the ergonomic fix for R0017 (no-same-type-params). Wrapping each same-typed parameter in its own newtype turns a silent argument swap into a compile error.

trust_std::newtype!(pub Width(u32));
trust_std::newtype!(pub Height(u32));

pub fn make_rect(width: Width, height: Height) -> u32 {
    width.0 * height.0
}
// make_rect(Height::new(5), Width::new(10)) is now a *type error*.

Generates a tuple struct with a public field plus new, into_inner, and From<inner>. It derives Debug, Clone, PartialEq (safe for any inner type, including f64). Add more — Copy, Eq, Hash, Ord — with an extra #[derive(…)] before the declaration (don’t re-list the three already derived):

trust_std::newtype!(#[derive(Copy, Eq, Hash, PartialOrd, Ord)] pub UserId(u64));