Storing derived classes in a vector of base class - vector

Question

I have seen several versions of my question, but I still cannot find an answer that works. I have defined a base class called TwoPort and two derived classes called Reflector and Waveguide as follows:
#include <vector>
class TwoPort
{
public:
TwoPort() { yeast = ywest = 0.0; }
~TwoPort() {}
double getyeast() { return yeast; }
double getywest() { return ywest; }
virtual void step(double xeast, double xwest);
protected:
double yeast;
double ywest;
};
class Reflector :
public TwoPort
{
public:
Reflector() { Gamma = 0.0; }
~Reflector() {}
void step(double xeast, double xwest) override;
void setReflection(double G) { Gamma = G; }
private:
double Gamma;
};
class Waveguide :
public TwoPort
{
public:
Waveguide() { oldest = 0; }
~Waveguide() {}
void step(double xeast, double xwest) override;
void setDelay(unsigned int delay);
private:
std::vector<double> eastBuffer, westBuffer;
unsigned int oldest;
};
My goal is to create a vector containing a mixture of Reflectors and Waveguides. Based on the answers to previous questions like mine, I have tried a number of approaches, but so far none have worked. For example:
int main()
{
std::vector<std::unique_ptr<TwoPort>> tpcascade;
tpcascade.emplace_back(new Reflector);
tpcascade.emplace_back(new Waveguide);
tpcascade.emplace_back(new Reflector);
tpcascade[0]->setRefection(0.25);
}
In this case, the compiler does not recognize the setReflection method. So I tried this:
int main()
{
std::vector<std::unique_ptr<TwoPort>> tpcascade;
auto ref = std::make_unique<Reflector>();
ref->setReflection(0.25);
tpcascade.emplace_back(ref);
}
In this case I can set the reflection but I get a lengthy and complex error message about the emplace statement.
Help!

Answer 1

Did some research and tried a variation on the second approach above:
int main()
{
std::vector<std::unique_ptr<TwoPort>> tpcascade;
auto ref = std::make_unique<Reflector>();
ref->setReflection(0.25);
tpcascade.push_back(std::move(ref));
}
Switching to shared_ptr seems to work too, and is a bit cleaner:
int main()
{
std::vector<std::shared_ptr<TwoPort>> tpcascade;
auto ref = std::make_shared<Reflector>();
ref->setReflection(0.25);
tpcascade.push_back(ref);
}
This also seems to work, but seems risky to me:
tpcascade.push_back(std::make_shared<Reflector>());
std::dynamic_pointer_cast<Reflector>(tpcascade[0])->setReflection(0.25);