Let me see if I understood you correctly. I cant have a code like this: extern "C" { int sum_of_numbers(){ std::vector<int> numbers {23, 445, 64}; int sum = 0; for (auto &item : numbers){ sum += item; } return sum; } } And I have to declare my function with inside the Datum sum_of_numbers(PG_FUNCTION_ARGS){ // function code here } Sorry for the log mails. I'm having problems to understand, how to change the construction of myfunc.cpp to run the code. -- Sent from: http://www.postgresql-archive.org/PostgreSQL-general-f1843780.html