fn arg_min(&self) -> usize {
        self.iter()
            .enumerate()
            .fold((0usize, f64::MAX), |acc, (ics, &val)| {
                if acc.1 > val {
                    (ics, val)
                } else {
                    acc
                }
            })
            .0
    }
arg min

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

fn main() {
let v = c!(1,3,2,4,3,7);
assert_eq!(v.arg_min(),0);

let v2 = c!(4,3,2,5,1,6);
assert_eq!(v2.arg_min(),4);
}
src/structure/vector.rs