TODO.md

• Persistent flags:

  Command.add_persistent_flag(..)

  Persistent flag must then be passed down the call stack.

• Required flags:

  Have an option to set bool required. Which is also validated (see args validator).

• Args validator for positional arguments Command.args (probably same function ptr as for run?)

  1. NoArgs
  2. ArbitraryArgs
  3. MinimumNArgs(int)
  4. MaximumNArgs(int)
  5. ExactArgs(int)
  6. RangeArgs(min, max)