Issue #20792 has been updated by Eregon (Benoit Daloze). In terms of performance though, both methods need 2 code range scans if the String is then `force_encoding(Encoding::UTF_8)` if valid and used later for some operation needing the code range. Maybe the String should stay in the argument encoding if it's valid in it? ---------------------------------------- Feature #20792: String#forcible_encoding? https://bugs.ruby-lang.org/issues/20792#change-110111 * Author: kddnewton (Kevin Newton) * Status: Open ---------------------------------------- I would like to add a method to String called `forcible_encoding?(encoding)`. This would return true or false depending on whether the receiver can be forced into the given encoding without breaking the string. It would effectively be an alias for: ```ruby def forcible_encoding?(enc) original = encoding result = force_encoding(enc).valid_encoding? force_encoding(original) result end ``` I would like this method because there are extremely rare but possible circumstances where source files are marked as binary but contain UTF-8-encoded characters. In that case I would like to check if it's possible to cleanly force UTF-8 before actually doing it. The code I'm trying to replace is here: https://github.com/ruby/prism/blob/d6e9b8de36b4d18debfe36e4545116539964ceeb/.... The pull request for the code is here: https://github.com/ruby/ruby/pull/11851. -- https://bugs.ruby-lang.org/