// ----------------------
// second_task_manager.h
// ----------------------

struct Triplet
{
    std::string dotName;
    std::string dotKeyPoints;
    int interpolationOrder;

    Triplet() :
         dotName(""), dotKeyPoints(""), interpolationOrder(0) {}
    Triplet(std::string dotName, std::string dotKeyPoints, int order) :
         dotName(dotName), dotKeyPoints(dotKeyPoints), interpolationOrder(order) {}

};

template<typename T>
class SecondTaskManager
{
    public:
    SecondTaskManager(const double T, std::string dotsFileName, std::string conditionsFileName);
    ...
    LocalSolver<T>* localSoverPtr_;
    void CalculateLocalPositions(); // ЭТОТ МЕТОД!!!

    private:
    std::vector<Triplet> triplets_;
};

#include"second_task_manager_impl.h"

// --------------------------
// second_task_manager_impl.h
// --------------------------

template<typename T>
inline void SecondTaskManager<T>::CalculateLocalPositions()
{
    std::vector<DotPosPair<T>> lol;

    localSoverPtr_->CalculateDotsLocalPos(triplets_);//(triplets_, &lol);
}

// ----------------------
// local_pos_solver.h
// ----------------------

#include"../SecTaskManager/second_task_manager.h"


template<typename T>
class LocalSolver
{
public:
    LocalSolver();
    ~LocalSolver();

    void CalculateDotsLocalPos(std::vector<Triplet> & triplets)
        { std::cout << "loln" }

private:
    InterpolationSolver<T>* solverPtr_;
    double T_;
};

#include"SecondTaskSecTaskManagersecond_task_manager.h"

int main()
{
    using std::cout;
    using std::endl;

    try
    {
        SecondTaskManager<float> manager(1.4, "SecondTaskFiles/dots", "/SecondTaskFiles/conditions");
        manager.CalculateLocalPositions(); // ВОТ МЕСТО ВЫЗОВА
    }
    catch (const std::exception& ex)
    {
        std::cout << ex.what();
    }
    ...
}

LocalSolver<T>* localSoverPtr_;