#include <string>
#include "tree.hh"
#include <iostream>
#include <memory>

class Base {
public:
    virtual void Serialize(std::ostream& os) const = 0;
    virtual ~Base() {}
};

auto getTree() {
    class ChildFirst :  public Base { virtual void Serialize(std::ostream& os) const { os << "First"  << std::endl; }; };
    class ChildSecond : public Base { virtual void Serialize(std::ostream& os) const { os << "Second" << std::endl; }; };
    class ChildThird :  public Base { virtual void Serialize(std::ostream& os) const { os << "Third"  << std::endl; }; };
    tree<std::unique_ptr<Base>> mTree;

    mTree.insert(mTree.begin(), std::make_unique<ChildFirst>());
    mTree.insert(mTree.begin(), std::make_unique<ChildThird>());
    mTree.insert(mTree.begin(), std::make_unique<ChildSecond>());

    return mTree;
}

int main() {
    const auto mTree = getTree();
    for (const auto& v : mTree) {
        v->Serialize(std::cout);
    }
    return 0;
}

Second
Third
First