Raises an error for any argument deemed invalid.

# You might use it in a module like this:
defmodule AtomEater do
  # atoms are valid
  def eat(atom) when is_atom(atom) do
    IO.puts "Mmm, that #{atom} was excellent!"
  end

  # anything other than atoms raises an exception
  def eat(invalid) do
    Idfk.raise_invalid_arg!(invalid)
  end
end

Basic usage:

iex> Idfk.raise_invalid_arg! "lol invalid"
** (RuntimeError) Invalid argument: "lol invalid"