Glad someone pointed that out. It is cheating. It is doing a lot of state transformations like in-place sorting / filtering. I'd like to see some real C++ funct

Glad someone pointed that out. It is cheating. It is doing a lot of state transformations like in-place sorting / filtering. I'd like to see some real C++ functional code here, using immutable data structures, not an imperative program using lambdas. I guess it would be both much harder to write (C++ is not really a functional language) and much slower, because dynamic memory allocation in C++ is more costly than in Java.