#includeIn this example, we create a new BSONObjBuilder object and use subarrayStart() to add a new sub-array called "myArray". We then add two elements to the sub-array using the reference to the sub-builder returned by subarrayStart(), and finally call done() to close the sub-array and get back to the main BSONObjBuilder object. The resulting BSON object is then serialized to a string using the obj().jsonString() method and can be used to interact with a MongoDB database.using namespace mongo; int main() { // create a new BSONObjBuilder object BSONObjBuilder builder; // add a new array to the BSON object and get a reference to the new sub-builder BSONObjBuilder& subBuilder = builder.subarrayStart("myArray"); // add some elements to the sub-array subBuilder.append("foo", "bar"); subBuilder.append("baz", 42); // close the sub-array and get back to the main builder subBuilder.done(); // serialize the BSON object to a string const std::string data = builder.obj().jsonString(); return 0; }