Сравнение производных классов - C++ - Ответ 6378451

#include <algorithm>
#include <iostream>
#include <memory>
#include <string>
#include <vector>
 
class BasePriority {
public:
    virtual int GetPriority() const = 0;
    virtual std::string Name() const = 0;
};
 
template <int p>
class Priority : public BasePriority {
public:
    int GetPriority() const override { return priority_; }
private:
    static const int priority_ = p;
};
 
class A : public Priority<2> {
public:
    std::string Name() const override {
        return "class A";
    }
};
 
class B : public Priority<1> {
public:
    std::string Name() const override {
        return "class B";
    }
};
 
typedef std::shared_ptr<BasePriority> BasePriorityPtr;
typedef std::vector<BasePriorityPtr> BasePtrContainer;
 
int main() {
    struct PriorityComparator {
        bool operator()(const BasePriorityPtr& lhs,
                const BasePriorityPtr& rhs) const {
            return lhs->GetPriority() < rhs->GetPriority();
        }
    };
        
    BasePtrContainer container {
        std::make_shared<B>(),
        std::make_shared<A>(),
        std::make_shared<B>(),
        std::make_shared<B>()
    };
    
    std::sort(container.begin(), container.end(), PriorityComparator());
    
    for (const auto& item : container) {
        std::cout << item->Name() << std::endl;
    }
    
    return 0;
}