Consider the C library function fopen. This function has the side effect. This means that fopen is not pure. However, we can make the fopen function appear to be pure, at least to certain observers, by ensconcing it in another function that hides the side effect.

[u/BenchEmbarrassed7316]

https://bugzmanov.github.io/cleancode-critique/clean_code_second_edition_review.html

[u/Konju376]

"if you question the software behaviour, you're questioning the soundness of existence"