Agreed, and what about the special case of std::transform in place on one range? That is to say when the output iterator actually points to the input range (this is the context of the question here).

No, `std::transform()` doesn’t modify its input. `std::for_each()` may, but `std::transform()` may not. `std::transform()` assigns its projection (the return value of the unary operation we pass in) “into” the output iterator.

So that’s arguably the important distinction from `std::for_each()`.