RocksWriteBatch.cpp

rocksdb::Slice key1 = "one";
rocksdb::Slice key2 = "two";
std::string bar = "bar";

db->Put(rocksdb::WriteOptions(), key1, bar);

std::string value;
rocksdb::Status s = db->Get(rocksdb::ReadOptions(), key1, &value);
if (s.ok()) {
    // atomically apply a set of updates
    rocksdb::WriteBatch batch;
    batch.Delete(key1);
    batch.Put(key2, value);
    s = db->Write(rocksdb::WriteOptions(), &batch);
}

s = db->Get(rocksdb::ReadOptions(), key1, &value);
assert(s.IsNotFound());
db->Get(rocksdb::ReadOptions(), key2, &value);
assert(value == bar);