class TrueClass def hash raise "TrueClass#hash should not be called" end end class FalseClass def hash raise "FalseClass#hash should not be called" end end class Integer def hash raise "Integer#hash should not be called" end end class Float def hash raise "Float#hash should not be called" end end class String def hash raise "String#hash should not be called" end end class Symbol def hash raise "Symbol#hash should not be called" end end