bbatsov/ruby-style-guide — pull request #294 by codezomb (2014-03-02 19:32:01+00:00)
Title: remove the constraint for not using double bang operator

The double bang `!!` is a standard ruby operator that is no more obscure than other literals such as `%w`, or `!`. Any misunderstanding, or misinterpretation is more of an issue of not understanding the ruby library, than it is the operator being obscure.