Question

I am trying to use Unicode variable names in g++, but it does not appear to work.

Does g++ not support Unicode variable names? Or is there some subset of Unicode (from which I’m not testing in)?

Answer 1

You have to specify the -fextended-identifiers flag when compiling. You also have to use \uXXXX or \uXXXXXXXX for Unicode (at least in GCC, it’s Unicode).

Identifiers (variable/class names, etc.) in g++ can’t be of UTF-8/UTF-16 or whatever encoding. They have to be:

identifier:
  nondigit
  identifier nondigit
  identifier digit

A nondigit is

nondigit: one of
  universalcharactername
  _ a b c d e f g h i j k l m n o p q r s t u v w x y z
  A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

And a universalcharactername is

universalcharactername:
  \UXXXXXXXX
  \uXXXX

Thus, if you save your source file as UTF-8, you cannot have a variable like:

int høyde = 10;

It had to be written like:

int h\u00F8yde = 10;

(which, in my opinion, would defeat the purpose. So just stick with a-z)