About the library <unistd.h>

Question

I would like to use the sleep () command, but for that I need to use the library mentioned above. The problem is that it is a c library, not c ++. I was wondering if there is such a library in c ++, Like <cstdlib> which is equivalent to <stdlib.h> in C.

OBS: I already tried to put the c in front and it gave error, and I also know that I can use the C libraries in c ++, however I am afraid that at some point it will not work.
Thanks for helping.