[Vala] string starts_with

[Juergen <jota gmx de>]

Hi,

I am wondering if there is some kind of string.starts_with method in
vala. 
I try to avoid a memory-allocating algorithm like 

        if ("Hello World"[0:5] == "Hello")

but do not know how to implement this without a starts_with method.
Are there any plans to implement it. I found such a method in the string
class at
http://gitorious.org/dova/dova-core/blobs/master/src/string.vala
but my valac 0.11.5 still does not know such a method.

Regards
juergen