Function split_opt 

pub fn split_opt(opt: &str) -> Option<(&str, &str)>

Split an option string into its prefix and name.

Examples

use click::parser::split_opt;

assert_eq!(split_opt("--name"), Some(("--", "name")));
assert_eq!(split_opt("-n"), Some(("-", "n")));
assert_eq!(split_opt("name"), None);
assert_eq!(split_opt("-"), None);