Using frozen_string_literal and unfreezing a string argument results in Ambiguous positive number operator warning · Issue #4630 · rubocop/rubocop · GitHub
Alternative ways to freeze a string in Ruby
Alternative ways to freeze a string in Ruby
Ruby 2.3.0 changes and features - Closer to Code
Frozen String Literal Magic Comment Causes "error in process filter: erm-parse: Beginning of buffer" · Issue #94 · zenspider/enhanced-ruby-mode · GitHub
How to specify `frozen_string_literal: true` | PPT