How to pass a pointer to member function to a template function

Here is my simplified code: S.h

class SBase {
...
public: 
    virtual std::vector<int32_t> getNumbersSet1();
    virtual std::vector<int32_t> getNumbersSet2();

}

class SDerived : public SBase {
...
public: 
    virtual std::vector<int32_t> getNumbersSet1() override;
    virtual std::vector<int32_t> getNumbersSet2() override;
}

class Base {
  public:
    virtual std::vector<int32_t> getNumbersSet1();
    virtual std::vector<int32_t> getNumbersSet2();
  protected:
    std::vector<SBase> sVec;

};

class Derived : public Base {
  public:
    virtual std::vector<int32_t> getNumbersSet1() override;
    virtual std::vector<int32_t> getNumbersSet2() override;
  protected:
    std::vector<SDerived> sVec;

}

Here is my simplified source code: S.cpp

std::vector<int32_t> Base::getNumbersSet1() {
    std::vector<int32_t> ret;
    for (SBase const& sbase : sVec)
    {
        std::vector<int32_t> tmp = sbase.getNumbersSet1();
        retval.insert(retval.end(), tmp.cbegin(), tmp.cend());
    }
    return retval;
}

std::vector<int32_t> Base::getNumbersSet2() {
    std::vector<int32_t> ret;
    for (SBase const& sbase : sVec)
    {
        std::vector<int32_t> tmp = sbase.getNumbersSet2();
        retval.insert(retval.end(), tmp.cbegin(), tmp.cend());
    }
    return retval;
}

std::vector<int32_t> Derived::getNumbersSet1() {
    std::vector<int32_t> ret;
    for (SDerived const& sderived : sVec)
    {
        std::vector<int32_t> tmp = sderived.getNumbersSet1();
        retval.insert(retval.end(), tmp.cbegin(), tmp.cend());
    }
    return retval;
}

std::vector<int32_t> Derived::getNumbersSet2() {
    std::vector<int32_t> ret;
    for (SDerived const& sderived : sVec)
    {
        std::vector<int32_t> tmp = sderived.getNumbersSet2();
        retval.insert(retval.end(), tmp.cbegin(), tmp.cend());
    }
    return retval;
}

Now, in order to remove some code duplicates I want to create a template function getNumbersSet() in my Base class, with a view to be able to call it from both getNumbersSet1() and getNumbersSet2() for both Base class and Derived class:

in the source file:

std::vector<int32_t> Base::getNumbersSet1() {
    return Base::getNumbersSet<SBase>(sVec, &Base::getNumbersSet1);
}

std::vector<int32_t> Base::getNumbersSet2() {
    return Base::getNumbersSet<SBase>(sVec, &Base::getNumbersSet2);
}

std::vector<int32_t> Derived::getNumbersSet1() {
    return Base::getNumbersSet<SDerived>(sVec, &Derived::getNumbersSet1);
}

std::vector<int32_t> Derived::getNumbersSet2() {
    return Base::getNumbersSet<SDerived>(sVec, &Derived::getNumbersSet2);
}

In order to achieve that This is what I have written the Base::getNumbersSet in the base class:

class Base {
    //.... as before
    
    template<class T>
    static std::vector<int32_t> getNumbersSet(std::vector<T> const& svec, std::vector<int32_t>(T::* getNumberFunc)() const )) {
        std::vector<int32_t> retval;
        for (T const& a : svec)
        {
            auto getNumbersOfT = std::bind(&T::getNumberFunc, a); // problem here
            std::vector<int32_t> tmp = getNumbersOfT();
            retval.insert(retval.end(), tmp.cbegin(), tmp.cend());
        }
    }

};

but this won't compile as on the problem line it complains that getNumberFunc is not a member function of type SBase or SDerived.

I have tried to use std::function, std::mem_fn as well but could not get it to work. I hope I have not made too many mistakes when reducing and my code and typing to post here. I appreciate your help.

A couple of problems: you want to be passing &SBase::getNumbersSet1 etc. as your function arguments, not &Base::getNumberSet1; and your pointer-to-member dereference syntax is wrong. You could change it to std::bind(getNumberFunc, a), or just call it like (a.*getNumberFunc)().

Here is your code with those changes, compiling: https://godbolt.org/z/o8Kc9oxjG

#include <cstdint>
#include <vector>

class SBase {
public: 
    virtual std::vector<int32_t> getNumbersSet1() const { return {1, 2}; }
    virtual std::vector<int32_t> getNumbersSet2() const { return {2, 3}; }
};

class SDerived : public SBase {
public: 
    virtual std::vector<int32_t> getNumbersSet1() const override { return {1, 2, 3}; }
    virtual std::vector<int32_t> getNumbersSet2() const override { return {2, 3, 4}; }
};

class Base {
  public:
    virtual std::vector<int32_t> getNumbersSet1();
    virtual std::vector<int32_t> getNumbersSet2();
    template<class T>
    static std::vector<int32_t> getNumbersSet(std::vector<T> const& svec, std::vector<int32_t>(T::* getNumberFunc)() const ) {
        std::vector<int32_t> retval;
        for (T const& a : svec)
        {
            std::vector<int32_t> tmp = (a.*getNumberFunc)();
            retval.insert(retval.end(), tmp.cbegin(), tmp.cend());
        }
        return retval;
    }
  protected:
    std::vector<SBase> sVec;

};

class Derived : public Base {
  public:
    virtual std::vector<int32_t> getNumbersSet1() override;
    virtual std::vector<int32_t> getNumbersSet2() override;
  protected:
    std::vector<SDerived> sVec;

};

std::vector<int32_t> Base::getNumbersSet1() {
    return Base::getNumbersSet(sVec, &SBase::getNumbersSet1);
}

std::vector<int32_t> Base::getNumbersSet2() {
    return Base::getNumbersSet(sVec, &SBase::getNumbersSet2);
}

std::vector<int32_t> Derived::getNumbersSet1() {
    return Base::getNumbersSet(sVec, &SDerived::getNumbersSet1);
}

std::vector<int32_t> Derived::getNumbersSet2() {
    return Base::getNumbersSet(sVec, &SDerived::getNumbersSet2);
}

int main() {
    Derived hello{};
}