Function qip::state_ops::sub_to_full

pub fn sub_to_full(
    n: u64, 
    mat_indices: &[u64], 
    sub_index: u64, 
    base: u64
) -> u64

Given the sub_index for the submatrix, and a base to overwrite values, get the full index for the 2^n by 2^n matrix.