Yes Cat Feces can safely be flushed down the toilet and is a much better way of disposing of the cat feces instead of in the trash can.
Flushing the cat feces down the toilet removes the smell from the house and makes your trashcan less smelly.
Just be sure to get most of the cat litter away from the cat poop before flushing it down the toilet since too much cat litter could clog the toilet.
I've flush cat poop down the toilet for years and never had a problem doing so.