Attribute Macro zero 

#[zero]

Available on crate feature bank only.

Mark a bank-0 helper that drives banked code.

Unlike the entry point, a helper may be called from inside any bank, so it cannot assume GroupZero: it must thread whatever token its caller holds and restore that bank. So #[bank::zero] is Warp-colored like #[bank] (called helper(args).drive()), but its Warp performs no bank switch, just forwards the caller’s token. Any banked call inside then switches C -> target -> C, leaving the caller’s bank exactly as it found it.

Works on a fn (incl. generics), an impl block (each method becomes such a helper, value.method(args).drive()), or a trait (its signatures are colored -> impl Warp, like a banked trait; a #[bank::zero] impl supplies bodies).

Examples

#[bank::zero]
pub fn update(state: u8) -> u8 {
    enemy::ai(state).drive()    // banked call inside; restores the caller's bank
}
// from anywhere with a bank token: `update(0).drive()`