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use gumdrop::Options;
// Define options for the program.
#[derive(Debug, Options)]
struct MyOptions {
// Options here can be accepted with any command (or none at all),
// but they must come before the command name.
#[options(help = "print help message")]
help: bool,
#[options(help = "be verbose")]
verbose: bool,
// The `command` option will delegate option parsing to the command type,
// starting at the first free argument.
#[options(command)]
command: Option<Command>,
}
// The set of commands and the options each one accepts.
//
// Each variant of a command enum should be a unary tuple variant with only
// one field. This field must implement `Options` and is used to parse arguments
// that are given after the command name.
#[derive(Debug, Options)]
enum Command {
// Command names are generated from variant names.
// By default, a CamelCase name will be converted into a lowercase,
// hyphen-separated name; e.g. `FooBar` becomes `foo-bar`.
//
// Names can be explicitly specified using `#[options(name = "...")]`
#[options(help = "make stuff")]
Make(MakeOpts),
#[options(help = "install stuff")]
Install(InstallOpts),
}
// Options accepted for the `make` command
#[derive(Debug, Options)]
struct MakeOpts {
#[options(help = "print help message")]
help: bool,
#[options(free)]
free: Vec<String>,
#[options(help = "number of jobs", meta = "N")]
jobs: Option<u32>,
}
// Options accepted for the `install` command
#[derive(Debug, Options)]
struct InstallOpts {
#[options(help = "print help message")]
help: bool,
#[options(help = "target directory")]
dir: Option<String>,
}
fn main() {
// Parse options from the environment.
// If there's an error or the user requests help,
// the process will exit after giving the appropriate response.
let opts = MyOptions::parse_args_default_or_exit();
println!("{:#?}", opts);
}
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