This apartment I just moved into had a curved shower curtain rod. The rod is made so it bows out significantly.
The tub is a conventional straight-sided tub that at least in my experience has been pretty standard in US houses built in the last 50 years or so.
There was a shower curtain on the curved rod but no liner. Naturally, during the first shower I took water went all over the floor.
From the tiny bit of online reasearch I've done I've determined the curved shower curtain rod is supposed to make the shower area bigger. It seems to me I've seen them recently in a few hotel bathrooms but in those cases the tubs themselves also bowed out, they didn't have straight sides.
So my question is are these curved rods supposed to be used with straight-sided tubs? How is one supposed to prevent water going all over the floor? If I tuck the curtain (or a liner) inside the tub that will prevent water going on the floor but it also pretty much eliminates the extra space-giving properties of the curved rod.
(I bought a cheap collapsible straight rod and put it inside the curved one and hung a liner on it, so the floor isn't getting wet anymore).