[owalt]

From the article:

> Normally, I would probably not make these member functions, but since The Witness is a more C++-ish codebase than my own, I thought it was more consistent with the style (and I don’t have a strong preference either way)

My interpretation of this is that normally he'd make plain C structs and functions that operate on them. So quite far from anything people would normally describe or think of as object oriented.