$ demo --help
A simple to use, efficient, and full-featured Command Line Argument Parser

Usage: demo[EXE] [OPTIONS] --name <NAME>

Options:
  -n, --name <NAME>    Name of the person to greet
  -c, --count <COUNT>  Number of times to greet [default: 1]
  -h, --help           Print help
  -V, --version        Print version

$ demo --name Me
Hello Me!

(version number and .exe extension on windows replaced by placeholders)