> There's no such a thing like "side-effect-free" code. This kind of like “Ceci n'est pas une pipe.” In that it’s useful to remind people that there is no such

> There's no such a thing like "side-effect-free" code. This kind of like “Ceci n'est pas une pipe.” In that it’s useful to remind people that there is no such thing as side-effect-free code, strictly speaking, but as soon as you remind people, you go back to talking about whether a particular piece of code has side effects. Someone points at object depicted in the painting and asks what it is, and you say “It’s a pipe.” Basically, to reason about code, it’s useful to ignore certain classes of side effects, most of the time.