(This "narrows" an integral value into a boolean 0/1, for those curious.)
I don’t get it, and tried to look it up without success. The only way I get it is if it also reverses logic was a 0 start value becomes true. But how is this different from !x ?
!!x gives you 0 if x is zero and 1 if x is anything else. !x gives you 1 if x is zero and 0 if x is anything else.