It's an interesting view because I find neatly compartmentalized functions easier to read and less error prone, though he does point out that copying chunks of code such as vector operations can lead to bugs when you forget to change some variable. I guess it depends on the function. Something like

    Vector c = dotProduct(a, b);

is readable enough and doesn't warrant inlining, I think. There's nothing about `dotProduct` that I would expect to have any side effects, especially if its prototype looks like:

    Vector dotProduct(Vector const& a, Vector const& b) const;