An example of a Rust-like `Option` enum in Ruby, see https://doc.rust-lang.org/rust-by-example/std/option.html

option.rb

# frozen_string_literal: true

# An example of a Rust-like `Option` enum in Ruby
module Option
  class NoneError < StandardError
    def message = "called #unwrap on a `None' value"
  end

  Some = Data.define(:unwrap) do
    def initialize(value) = super
  end

  None = Data.define do
    def unwrap = raise NoneError
  end
end

include Option

# An integer division that doesn't `raise ZeroDivisionError`
def checked_division(dividend, divisor)
  if divisor.zero?
    # Failure is represented as the `None` variant
    None.new
  else
    # Result is wrapped in a `Some` variant
    Some.new(dividend / divisor)
  end
end

# This function handles a division that may not succeed
def try_division(dividend, divisor)
  # `Option` values can be pattern matched, just like other enums
  case checked_division(dividend, divisor)
  in None
    puts "#{dividend} / #{divisor} failed!"
  in Some(quotient)
    puts "#{dividend} / #{divisor} = #{quotient}"
  end
end

try_division(4, 2)
#>> 4 / 2 = 2
try_division(1, 0)
#>> 1 / 0 failed!