Help, what is the code mean?

[ag0aep6g]

On Tuesday, 28 April 2020 at 20:48:57 UTC, Net wrote:
> () { ... } ();
>
> Is there a name of this kind of function in D? unnamed? 
> anonymous?

The spec uses "anonymous". Syntactically, `() { ... }` is a 
function literal.

There is a section called "Anonymous Functions and Anonymous 
Delegates" [1], but it's just a link to "Function Literals":

https://dlang.org/spec/expression.html#function_literals

To be clear, the second set of parentheses in `() { ... } ()` 
just calls the anonymous function. You could equivalently write 
it like this:

     alias f = () { ... };
     f();


[1] https://dlang.org/spec/function.html#anonymous