The function is defined below in the same file: https://github.com/telefonicaid/fiware-orion/pull/276/files#diff-4d88547ce2fb3f34e774c32845272c20R93

Note that this function is only used by MongoCommonUpdate.cpp. Actually, the idea is not to expose it to other modules: only MongoCommonUpdate.cpp should be using it.

Moreover, this "problem" is due to the need of two recursive related functions: F1 that calls F2 and F2 that calls F1.

So, maybe I should define it in MongoCommonUpdate.h but without "extern", to avoid other modules using it?