Macro doe::vec_element_to_string

macro_rules! vec_element_to_string {
    ($vec:expr) => { ... };
}

convert vec item to String,return Vec<String>

use doe::*;
let v1 = vec_element_to_string!(vec!["15.", "2.9"]);
let v2 = vec_element_to_string!(vec![15, 2]);
let v3 = vec_element_to_string!(vec![0.15, 0.2]);
assert_eq!(vec!["15.", "2.9"], v1);
assert_eq!(vec!["15", "2"], v2);
assert_eq!(vec!["0.15", "0.2"], v3);