C++ vector issue - 'LNK2001: unresolved external symbol private: static…'

Question

Before anyone calls me out for not looking at pre-existing questions, I have looked and realise that it is to do with declaration, but I still can\'t get it to work (might be so

Answer 1

In your .cpp file, you need to add the definitions of the static variables:

vector Manager::airports;
vector Manager::flights;

See Why are classes with static data members getting linker errors? from the C++ FAQ.