Macro duck_state 

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

Returns a clone of the current scalar function’s State, from inside a #[duckdb_scalar(state = ...)] function body.

Type must be Clone — the macro always returns an independently owned value, never a reference into ambient context.

Panics

Panics if called outside a scalar function callback, or if Type doesn’t match the function’s declared state type — contained by this crate’s callback machinery, so it always surfaces as a normal query error, never undefined behavior.