function could not be resolved c++

Question

I am trying to make a more general filter so I defined with typedef a pointer to function. But I receive an error in the DynamicVector* filterByQuantity(int quantity) function. This is the whole code for what I am trying to do:

controller.h

typedef int (*filterFunc)(Medicine* criteria, Medicine*);
DynamicVector<Medicine>* filter2(Medicine* criteria, filterFunc f);

controller.cpp

    #include "controller.h"

int filterByQuantityLess(Medicine* criteria, Medicine* p) {
    if (criteria->getQuantity() > p->getQuantity()) {
        return 0;
    }
    return 1;
}

DynamicVector<Medicine>* Controller::filter2(Medicine* criteria, filterFunc f){
    DynamicVector<Medicine>* medList = repo->getAll();
    DynamicVector<Medicine>* rez = new DynamicVector<Medicine>();
    for(int i=0; i < medList->getLen(); i++){
        Medicine* m = new Medicine(medList->getElementAtPosition(i));
        if(!f(criteria, m)){
            rez->addElement(*m);
        }
    }
    return rez;
}

DynamicVector<Medicine>* filterByQuantity(int quantity){
    Medicine* criteria = new Medicine(1,"",1,quantity);
        DynamicVector<Medicine>* rez = filter2(criteria, filterByQuantityLess); //error

    return rez;
}

the error is: Multiple markers at this line - 'filter2' was not declared in this scope - Function 'filter2' could not be resolved

Where am I doing wrong? The filter2 function returns a DynamicVector so I don't understand why it doesn't work.

Answer 1

Because filter2´s declaration and its implementation differs.

Look at how you're prototyping it on line 2 and how you implements it. Filter2 should either be declared as part of the Controller scope or as part of the global scope, not both.