64 bit size_t

[Steve Teale]

> Rather than change it to int/ulong, just change it to 'size_t 
> len = parent.children.length+1' (or auto instead of size_t). 
> This way it's proper for both 32-bit and 64-bit and you don't 
> need to worry about architecture. If you do need a signed 
> version, you can use ptrdiff_t.

Yup, that's what I did when my head returned to its usual postion 
;=)