Question

Say we have a string with binary bson data inside. How to load it into bson object?

Answer 1

I think there’s an example to do just that on that same page:

BSONObjBuilder b;
b << "name" << "Joe" << "age" << 33;
BSONObj p = b.obj();

That is, BSONObjBuilder has a stream operator for const char *.

From the docs:

BSONObjBuilderValueStream & operator<< (const char *name)
Stream oriented way to add field names and values.