1use core::iter;
 2
 3use crate::alloc::AllocationMode;
 4
 5pub(crate) fn modes() -> impl Iterator<Item = AllocationMode> {
 6    use AllocationMode::*;
 7    [Constant, Input, Witness].into_iter()
 8}
 9
10pub(crate) fn combination<T: Clone>(
11    mut i: impl Iterator<Item = T>,
12) -> impl Iterator<Item = (AllocationMode, T)> {
13    iter::from_fn(move || i.next().map(|t| modes().map(move |mode| (mode, t.clone()))))
14        .flat_map(|x| x)
15}