Enum ParsingStyle Copy item path

use gumdrop::{Options, ParsingStyle};

#[derive(Options)]
struct MyOptions {
    // If the "-o" is parsed as an option, this will be `true`.
    option: bool,
    // All free (non-option) arguments will be collected into this Vec.
    #[options(free)]
    free: Vec<String>,
}

// Command line arguments.
let args = &["foo", "-o", "bar"];

// Using the `AllOptions` parsing style, the "-o" argument in the middle of args
// will be parsed as an option.
let opts = MyOptions::parse_args(args, ParsingStyle::AllOptions).unwrap();

assert_eq!(opts.option, true);
assert_eq!(opts.free, vec!["foo", "bar"]);

// Using the `StopAtFirstFree` option, the first non-option argument will terminate
// option parsing. That means "-o" is treated as a free argument.
let opts = MyOptions::parse_args(args, ParsingStyle::StopAtFirstFree).unwrap();

assert_eq!(opts.option, false);
assert_eq!(opts.free, vec!["foo", "-o", "bar"]);