Function change_case::change_case

pub fn change_case(input: &str, config: Config) -> String

Core function to change case

use regex::Regex;
use change_case::{change_case, Config};
let config = Config::default()
    .set_split_regex(vec![Regex::new("([a-z])([A-Z0-9])").unwrap()]);
assert_eq!(change_case("camel2019", config), "camel 2019");
assert_eq!(change_case("camel2019", Config::default()), "camel2019");