https://issues.dlang.org/show_bug.cgi?id=15710
--- Comment #2 from Jonathan M Davis <[email protected]> --- Well having isValidUTF rather than validate would just make it so that you can use an if-else block instead of a try-catch. It wouldn't really clean that code up much. If you really want to clean up what you're doing in that example, you need to use byCodeUnit or byUTF, which use the replacement character. In that case, you wouldn't need to check for valid Unicode. If you want a string out the other side instead of a range of code units or code points, you then just call to!string or toUTF8 on it. e.g. auto codeUnits = str.byCodeUnit(); or auto dchars = str.byDchar(); // byUTF!dchar or str = str.byCodeUnit().to!string(); Now, if you want a string and don't want to allocate a new string if the string is valid, then you'd need to check whether the string is valid Unicode, but in that case you still don't need anything as complicated as what you wrote for toValidUTF. You'd just need something like try str.validate(); catch(UnicodeException) str = str.byCodeUnit().to!string(); and if we had isValidUTF, then you'd have if(!str.isValidUTF()) str = str.byCodeUnit().to!string(); So, while isValidUTF would help, it's mostly just getting rid of an unnecessary exception, which does clean up the code in this case, but not drastically. It's byCodeUnit or byUTF that really clean things up here. Now, as for adding isValidUTF, I have a PR for it in the PR queue, and Andrei approved the symbol, but he rejected the implementation. He basically wanted me to completely redesign how decode works internally and that the superficial changes I had made to make it work with isValidUTF were too ugly to live. So, at some point here, I need to go back and figure out how to rework all that again, which is not going to be pretty. --
