Issue #20792 has been updated by Eregon (Benoit Daloze). Right, that would also solve this specific usage. However I think `String#with_encoding` is a good general method to have, as for instance there are [lots of `.dup.force_encoding`](https://github.com/search?q=.dup.force_encoding+language%3ARuby&type=code&l=Ruby). It's one of the rare cases where Ruby core API don't have a nice way to do something in a non-mutating manner so that would fix it. It's especially striking for frozen literal strings where one just wants it in some specific encoding, but currently one has to `"foo".dup.force_encoding(SOME_ENCODING)`. There is `String#b` but that's only for the BINARY encoding (and the name is not really clear). ---------------------------------------- Feature #20792: String#forcible_encoding? https://bugs.ruby-lang.org/issues/20792#change-110114 * 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/