这是否符合您的要求？

require 'bigdecimal/math' # a module from stdlib
bm = BigMath # a module is just an object
BigMath = nil # yields a warning, but BigMath is gone.
puts bm.log(10, 40).to_s # it's alter ego lives.
#=> 0.230258509299404568401799145468436420760110148862877297632502494462371208E1