Simple Macro with `do` keyword

simple_macro.ex

defmodule Foo do
  defmacro hello(do: func) do
    IO.puts "Hello"
    func
  end
end

defmodule Bar do
  require Foo

  def hello_world do
    Foo.hello do
      IO.puts "World"
    end
  end
end

Bar.hello_world

# Hello
# World