better_to_i.rb

module BetterToInteger
  def self.included(string_class)
    string_class.alias_method_chain :to_i, :logging
  end

  def to_i_with_logging
    returning(to_i_without_logging) do |new_value|
      logger.log "Converting from #{self} to #{new_value}"
    end
  end
end

String.send :include, BetterToInteger