Function mat2::rotation

pub fn rotation<'out, T>(out: &[T; 4]) -> T where
    T: Clone + Float, 

Example

use std::f32;
let mut m = mat2::new_identity::<f32>();
mat2::set_rotation(&mut m, &f32::consts::FRAC_PI_2);
assert_eq!(mat2::rotation(&m), f32::consts::FRAC_PI_2);