templates.cpp

#include <stdlib.h>
#include <iostream>
using namespace std;

//dog.h
class Dog {
    public:
        Dog(string name);
        string say_hello();
private:
        string name;

};

//dog.cpp
Dog::Dog(string dogName) {
    name = dogName;
};

string Dog::say_hello() {
    return "Woff, I am " + name;
};

//cat.h
class Cat {
    public:
        Cat(string name);
        string say_hello();
    private:
        string name;
};

//cat.cpp
Cat::Cat(string catName) {
    name = catName;
};

string Cat::say_hello() {
    return "Miaou, I am " + name;
};

//main.cpp
template <class T>
string helloAnimal (T * entity) {
    return (string) entity->say_hello();
}

int main(int argc, const char * argv[])
{
    Dog d("Foo");
    Cat c("Barry");

    cout << helloAnimal<Dog>(&d) << endl;
    cout << helloAnimal<Cat>(&c) << endl;

    return 0;
}