func (iter *Iterator) Valid() bool {
	return C.rocksdb_iter_valid(iter.it) != 0
}
Valid returns false only when an Iterator has iterated past either the
first or the last key in the database. An iterator is either positioned
at a key/value pair, or not valid.
package rocksdb
import "C"
import (
	"bytes"
	"errors"
	"unsafe"
)
type Iterator struct {
	it *C.rocksdb_iterator_t
}
func NewNativeIterator(c unsafe.Pointer) *Iterator {
	return &Iterator{it: (*C.rocksdb_iterator_t)(c)}
}