I am wondering how these bathrooms are done without a shower curb:

http://www.diydoctor.org.uk/project_...om/wetroom.jpg
http://www.impey-showers.com/prod_img/hd6_s_1.jpg

There is still a shower pan below, or no? Or you have to consider the
entire bathroom a giant shower pan and slope everything to the shower
drain?

I have a bathroom I am remodeling where the space between the shower
edge and the closet flange is two inches less than the minimum
clearance (16") and I don't want a 4"-6" thick curb to hold up the
shower door, I was thinking this may be the solution, but may be there
are other creative ways.

Thanks,

MC