Module macros 

Convenience macros for creating specs with minimal boilerplate.

Examples

use usage::{spec_flag, spec_arg, spec_cmd};

// Create a flag
let verbose = spec_flag!("-v", "--verbose");
let output = spec_flag!("--output" => "<file>"; help = "Output file");

// Create an argument
let file = spec_arg!("file"; required = true);
let files = spec_arg!("files"; var = true, var_min = 1);

// Create a command
let cmd = spec_cmd!("install";
    help = "Install packages",
    aliases = ["i", "add"]
);