When implementing the CRUD spec's error handling portion in the C++11 driver (link: https://github.com/mongodb/specifications/blob/master/source/crud/crud.rst#error-handling) i found it was not possible to retrieve the information mandated by the spec in the case a bulk write error.

That is, in the case of an error it should be possible to retrieve:

• the requests that were sent to the server
• the requests that were not sent to the server
• any errors that the server returned (including the request that triggered the error, and the index of the corresponding request in the original list of requests)

This would require a fairly large addition to the ABI, but it seems like it could be possible to do in a backwards compatible way.