Complement of empty index vector is empty index vector again

Question

I know this question was already posted but the answer was a trick to solve the given problem some other way, but the core question remained unanswered.

The question is

Answer 1

somevector <- c(1:5,NA,8)
sumvec<-subset(somevector,!is.na(somevector))

Not too sure if this is what you want, but let me know if you wanted something different so I can correct my answer. The answer hashtagged is an alternative answer if this is what you were looking for.