fn add_col(&self, v: &Self::Vec) -> Matrix {
        assert_eq!(self.row, v.len());
        match self.shape {
            Shape::Col => {
                let mut m = self.clone();
                m.data.extend_from_slice(&v[..]);
                m.col += 1;
                m
            }
            Shape::Row => {
                let mut m = self.change_shape();
                m.data.extend_from_slice(&v[..]);
                m.col += 1;
                m
            }
        }
    }
Add column

```
#[macro_use]
extern crate peroxide;
use peroxide::fuga::*;

fn main() {
let a = ml_matrix("1 2 3;4 5 6");
let b = c!(7,8);
let c = a.add_col(&b);
assert_eq!(c, ml_matrix("1 2 3 7;4 5 6 8"));
}
```
src/traits/sugar.rs