Function getopts::optflagUnstable

pub fn optflag(short_name: &str, long_name: &str, desc: &str) -> OptGroup

Create a long option that is optional and does not take an argument.

• short_name - e.g. "h" for a -h option, or "" for none
• long_name - e.g. "help" for a --help option, or "" for none
• desc - Description for usage help