Issue #7795 has been reported by Student (Nathan Zook). ---------------------------------------- Feature #7795: Symbol.defined? and/or to_existing_symbol https://bugs.ruby-lang.org/issues/7795 Author: Student (Nathan Zook) Status: Open Priority: Normal Assignee: Category: core Target version: next minor I'm pulling this out from deep in the discussions of issue http://bugs.ruby-lang.org/issues/7791, Let Symbols be Garbage Collected. The problem is that the extreme utility of symbols makes them enticed to use, which results in a DOS vulnerability. My proposal is to add either of a pair of methods that would make it easy to defend against a DOS along these lines. #1) Symbol.defined? In existing code, it would might like this: class Symbol def self.defined?(string) all_symbols.any?{|sym| sym.to_s == string} end end #2) to_existing_sym. This would be defined in the same places as to_sym, but would through an argument error if the symbol did not already exist. -- http://bugs.ruby-lang.org/