mongoc_client_set_read_concern()

void
mongoc_client_set_read_concern (mongoc_client_t              *client,
                                const mongoc_read_concern_t  *read_concern);

Sets the read concern for the client. This only affects future operations, collections, and databases inheriting from client.

The default read concern is MONGOC_READ_CONCERN_LEVEL_LOCAL. This is the correct read concern for the great majority of applications.

It is a programming error to call this function on a client from a mongoc_client_pool_t. For pooled clients, set the read concern with the MongoDB URI instead.