How do I copy a column?

nalgebra
1 
let mut m = nalgebra::Matrix2x3::new(1.1, 1.2, 1.3,
                                     2.1, 2.2, 2.3);
m.column_mut(0).copy_from(&m.column(1));

fails because of the borrowing rules.

I’m trying to get:

let mut m = nalgebra::Matrix2x3::new(1.2, 1.2, 1.3,
                                     2.2, 2.2, 2.3);

I want to avoid any copying/cloning to temporary structures.