Re: Three Cool Things about D

[Steven Schveighoffer via Digitalmars-d-announce]

On 12/22/15 1:29 PM, David Nadlinger wrote:

---
ulong factorial(this n) {
     return n <= 1 ? 1 : n * factorial(n - 1);
}
---

Am I missing some new feature here? What does the 'this' mean?

-Steve