Learning to XML with D

[Adam D. Ruppe via Digitalmars-d-learn]

On Friday, 6 February 2015 at 09:15:54 UTC, Derix wrote:
> OK, we're doing some event-base parsing, reacting with a lambda 
> function on encountering so-and-do tag, à la SAX. (are we ?)

yeah

> What I don't quite grab is the construct (in Element e) , 
> especially the *in* part.

Function parameters in D can be qualified as in or out, 
optionally:

http://dlang.org/function.html#parameters

(in Element e) means you are taking an argument of type Element 
that you only intend to take in to look at. An "in" parameter is 
const and you are not supposed to store a reference to it.

So basically, `in` on a function parameter means "look, don't 
touch".