Indentation by itself can be tricky, too. Is your code correctly indented when you copy and paste it somewhere? Can it correctly re-indent code that got mangled

Indentation by itself can be tricky, too. Is your code correctly indented when you copy and paste it somewhere? Can it correctly re-indent code that got mangled for some reason? How well does indentation cope with non-standard language extensions (think Qt or C++ macros)? So I would not call that trivial.