Yep I pretty much did the same as Nai with my DS - with a cyclonic toddler who wore me out during the day, getting up in the middle if the night was so difficult!

And freezing cold - me and bubs were both warmer lying in bed together.

As cherished has mentioned, there are co-sleeping devices that you could look into but I think most people don't really bother with them.

The only thing I did differently to Nai is my arm was just above DS's head, but same concept, with my arm out like that it was virtually impossible to roll.

I'd put DS down in his cradle (now cot) then when he woke for his early morning feed it'd ve straight into bed with us. Then he'd be back into his cot once my DD woke. So we only coslept for a few hours each night.

We've stopped now - but only because I was getting a stiff neck from the position I was lying in!

We had one funny moment where DD was sick and was waking up at 4, 5am... DH started bringing her into our bed as well - so we'd have DS on the outside (with a pillow so he didn't fall out), then me, then DD and then DH. Poor DH (6'2" and about 120kg) would end up with his butt hanging off the edge of the bed and growled at me one morning "we need a bigger bed!!!"