Function getopts::optopt

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

Unstable (rustc_private)

: use the crates.io getopts library instead

Create a long option that is optional and takes 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
• hint - Hint that is used in place of the argument in the usage help, e.g. "FILE" for a -o FILE option