Passing Structs to function like in C

[D.Rex via Digitalmars-d-learn]

Hi,

This has probably been asked many times before, but after search 
for hours and hours I can't find an answer.  I have seen in C an 
extern function taking in a struct as one of its parameters, like 
so:

extern unsigned long free_page_tables(struct task_struct * tsk);

I was wondering how this is achieved in D, or if D has an 
alternative implementation of this.

Cheers.