Function treez::backtrack::compute

pub fn compute<Fcandidate, Fsoln>(
    arr: &[i32], 
    out: &mut Vec<i32>, 
    n: i32, 
    f_candidate: &mut Fcandidate, 
    f_is_solution: &mut Fsoln
) -> Vec<Vec<i32>> where
    Fsoln: FnMut(&[i32], i32, i32) -> bool,
    Fcandidate: FnMut(&[i32], i32) -> Vec<i32>,