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unary_operators.md

➕ Unary Operators for Type Conversion​

Ruby supports defining +@ and -@ for unary plus/minus behavior, enabling custom type conversions or transformations. Use them sparingly for numeric-like or wrapper objects to keep code intuitive.

class Temperature
  def initialize(celsius)
    @c = celsius
  end
  def +@
    @c * 9.0/5 + 32 # to Fahrenheit
  end
  def -@
    -@c # invert sign
  end
end

t = Temperature.new(25)
puts +t  # => 77.0 (°F)
puts -t  # => -25