Calls `this(this)` extra with delegate stuff in the code

[Basile B. via Digitalmars-d-learn]

On Sunday, 22 January 2017 at 03:42:21 UTC, Ali Çehreli wrote:
> On 01/21/2017 07:22 PM, Basile B. wrote:
>> [...]
>
> Wow! Thanks.
>
> I know about 'alias this' but this (pun!) is new to me. TIL 
> indeed and WAT!!!! (four exclamation marks is right in this 
> case. :o) )
>
> import std.stdio;
>
> struct S {
>     void foo(this a = () {
>             static assert(is(this));     // 'this' is a type
>             return S();
>         }()) {
>
>         static assert(is(typeof(this))); // 'this' is an 
> expression
>         writeln("foo called for ", this);
>     }
>                                          // WAT!!!!
> }
>
> void main() {
>     auto s = S();
>     s.foo(s);
> }
>
> Ali

Same mood. I'm quite astonished to see that something like that 
still can be discovered, years after the language creation.