Macro unsafe_unions::unsafe_unions

macro_rules! unsafe_unions {
    () => { ... };
    (
        pub union $union:ident: $repr:ty {
            $($variant:ident: $variant_ty:ty),+
        }
        $($ff:tt)*
    ) => { ... };
    (
        pub union $union:ident: $repr:ty {
            $($variant:ident: $variant_ty:ty),+,
        }
        $($ff:tt)*
    ) => { ... };
    (
        union $union:ident: $repr:ty {
            $($variant:ident: $variant_ty:ty),+
        }
        $($ff:tt)*
    ) => { ... };
    (
        union $union:ident: $repr:ty {
            $($variant:ident: $variant_ty:ty),+,
        }
        $($ff:tt)*
    ) => { ... };
    (@impl_common $union: ident; $repr:ty; $($variant:ident: $variant_ty:ty),+) => { ... };
    (@impl_pub $union: ident; $repr:ty; $($variant:ident: $variant_ty:ty),+) => { ... };
    (@impl_non_pub $union: ident; $repr:ty; $($variant:ident: $variant_ty:ty),+) => { ... };
}