BigDecimal

BigDecimals are duplicable:

BigDecimal.new(“1.2”).duplicable? # => true BigDecimal.new(“1.2”).dup # => #<BigDecimal:…,'0.12E1',18(18)>

# File activesupport/lib/active_support/core_ext/object/duplicable.rb, line 111
def duplicable?
  true
end