Identifying polimorphic types without using RTTI or type mappings, C++ (gcc)

Identifying polimorphic types without using RTTI or type mappings

//Title of this code
//g++  4.8.2

#include <iostream>
#include <vector>
#include <algorithm>
#include <memory>

struct DieselCar;
struct PetrolCar;

struct Car
{
    virtual const char * getName() const = 0;
    virtual bool hasType(const Car*) const { return true; }
    virtual bool hasType(const DieselCar*) const { return false; }
    virtual bool hasType(const PetrolCar*) const { return false; }
};

struct DieselCar : public Car
{
    const char * getName() const { return "DieselCar"; }
    
    bool hasType(const DieselCar*) const { return true; }
};

struct PetrolCar : public Car
{
    const char * getName() const { return "PetrolCar"; }
    
    bool hasType(const PetrolCar*) const { return true; }
};

template<class T>
struct HasType
{
    bool operator()(const std::shared_ptr<Car> sec) const
    {         
        return sec->hasType(static_cast<T*>(NULL));
    }
};

int main()
{
    std::vector<std::shared_ptr<Car>> securities;
    
    securities.push_back(std::make_shared<DieselCar>());
    securities.push_back(std::make_shared<PetrolCar>());
    securities.push_back(std::make_shared<DieselCar>());
    securities.push_back(std::make_shared<DieselCar>());
    securities.push_back(std::make_shared<PetrolCar>());
    securities.push_back(std::make_shared<DieselCar>());
    securities.push_back(std::make_shared<PetrolCar>());
    securities.push_back(std::make_shared<DieselCar>());
    
    std::cout << securities.size() << std::endl;
    
    securities.erase(std::remove_if(securities.begin(), securities.end(), HasType<DieselCar>()), securities.end());
    
    std::cout << securities.size() << std::endl;
    
}


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