Function spsheet::column_and_row_to_index

pub fn column_and_row_to_index<'a, S>(value: S) -> Option<(usize, usize)> where
    S: Into<Cow<'a, str>>, 

Column and row String index to usize index pair

use spsheet::*;
assert_eq!(Some((701,11)), column_and_row_to_index("ZZ12"));