[Koshkin]

“Modifying things in place” is, from the logical standpoint, an unnatural and even dangerous thing. A person that is not familiar with (imperative) programming often has a hard time understanding variables and assignments (similar to some programmers not understanding pointers). Mathematics doesn’t have assignments, either. That should tell you something...

[vkou]

It mostly tells me that mathematics does not care about runtime or space performance. Which is fine, because mathematics is about solving abstract problems, not getting a Turing machine to solve concrete problems.

[recursive]

In that case, quicksort requires danger and artifice. In any case, it's not quicksort.