pkg syscall (darwin-arm64), const IPV6_MAX_GROUP_SRC_FILTER = 512
pkg syscall (darwin-arm64), const IPV6_MAX_GROUP_SRC_FILTER ideal-int
pkg syscall (darwin-arm64), const IPV6_MAX_MEMBERSHIPS = 4095
pkg syscall (darwin-arm64), const IPV6_MAX_MEMBERSHIPS ideal-int
pkg syscall (darwin-arm64), const IPV6_MAX_SOCK_SRC_FILTER = 128
pkg syscall (darwin-arm64), const IPV6_MAX_SOCK_SRC_FILTER ideal-int

// removing those divisible by 'prime'.
func filter(src <-chan int, dst chan<- int, prime int) {
	for i := range src {  // Loop over values received from 'src'.
		if i%prime != 0 {
			dst <- i  // Send 'i' to channel 'dst'.
		}
	}
}

// The prime sieve: Daisy-chain filter processes together.
func sieve() {
	ch := make(chan int)  // Create a new channel.