It's not just nontrivial for C++, you need a full template engine just to properly parse it [1]. Same thing for languages with a lisp-like macro system. Or languages that allow dynamic redefinition od symbols [2].

[1] http://blog.reverberate.org/2013/08/parsing-c-is-literally-u...

[2] https://www.perlmonks.org/?node_id=663393