link error

error LNK2019: unresolved external symbol "class std::vector<int,class std::allocator<int> > __cdecl alternateMerge<int>(class std::vector<int,class std::allocator<int> > &,class std::vector<int,class std::allocator<int> > &)" ( $alternateMerge@H@@YA AV $vector@HV $allocator@H@std@@@std@@AAV01@0@Z) referenced in function _main

i have the following code in my program which i suspect is the cause, but cant find a way to resolve it.

i'm trying to merge two vectors and return a vector to main.

thanks.