Macro bytemuck::impl_unsafe_marker_for_simd

macro_rules! impl_unsafe_marker_for_simd {
    ($(#[cfg($cfg_predicate:meta)])? unsafe impl $trait:ident for $platform:ident :: {}) => { ... };
    ($(#[cfg($cfg_predicate:meta)])? unsafe impl $trait:ident for $platform:ident :: { $first_type:ident $(, $types:ident)* $(,)? }) => { ... };
}

A macro to implement marker traits for various simd types. #[allow(unused)] because the impls are only compiled on relevant platforms with relevant cargo features enabled.