fn par_reduce<F, T>(&self, _init: T, f: F) -> f64
    where
        F: Fn(f64, f64) -> f64 + Send + Sync,
        T: Into<f64> + Send + Sync + Copy,
    {
        self.par_iter()
            .cloned()
            .reduce_with(|x, y| f(x, y))
            .expect("Unable to perform parallel reduce operation")
    }
reduce for `Vec<f64>`

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

fn main() {
let a = seq!(1,100,1);
assert_eq!(a.par_reduce(0, |x,y| x + y), 5050f64);
}
```
src/structure/vector.rs