C++11 自定义比较类在std::set容器中指向用户定义类的指针时无法正常工作

C++11 自定义比较类在std::set容器中指向用户定义类的指针时无法正常工作,c++11,pointers,set,user-defined-types,custom-compare,C++11,Pointers,Set,User Defined Types,Custom Compare,我不明白为什么在这个代码示例中,std::set容器没有按照我所定义的比较类对实体进行排序。有人能帮我吗?谢谢 #include <iostream> #include <set> class Entity { public: int num; Entity(int num):num(num){} bool operator< (const Entity& _entity) const { return (this->num &

我不明白为什么在这个代码示例中,std::set容器没有按照我所定义的比较类对实体进行排序。有人能帮我吗?谢谢

 #include <iostream>
 #include <set>

 class Entity {
 public:
 int num;
 Entity(int num):num(num){}
     bool operator< (const Entity& _entity) const { return (this->num < _entity.num); }
 };

 struct my_cmp {
     bool operator() (const Entity* lhs, const Entity* rhs) const { return (lhs < rhs); }
 };

 class EntityManager {
     private:
        std::set<Entity*, my_cmp> entities;
   public:
        void AddEntity(int num) { entities.insert(new Entity(num)); }
        void ListAllEntities() const {
              unsigned int i = 0; 
              for (auto& entity: entities) {
                  std::cout << "Entity[" << i << "]: num:" << entity->num << std::endl;
                  i++;
              }
         }
};

int main(void) {
    EntityManager manager;
    manager.AddEntity(2);
    manager.AddEntity(1);
    manager.AddEntity(4);
    manager.AddEntity(3);
    manager.ListAllEntities();
    return 0;
}
#包括
#包括
类实体{
公众:
int-num;
实体(int num):num(num){}
布尔运算符<(const-Entity&_-Entity)const{return(this->num<_-Entity.num);}
};
结构我的cmp{
布尔运算符()(常量实体*lhs,常量实体*rhs)常量{return(lhsstd::cout您需要取消对指针的引用
*lhs<*rhs
。您只是在比较当前指针的值,因此您的顺序取决于它们在内存中的位置

#include <iostream>
 #include <set>

 class Entity {
 public:
 int num;
 Entity(int num):num(num){}
     bool operator< (const Entity& _entity) const { return (this->num < _entity.num); }
 };

 struct my_cmp {
     bool operator() (const Entity* lhs, const Entity* rhs) const { return (*lhs < *rhs); }
 };

 class EntityManager {
     private:
        std::set<Entity*, my_cmp> entities;
   public:
        void AddEntity(int num) { entities.insert(new Entity(num)); }
        void ListAllEntities() const {
              unsigned int i = 0; 
              for (auto& entity: entities) {
                  std::cout << "Entity[" << i << "]: num:" << entity->num << std::endl;
                  i++;
              }
         }
};

int main(void) {
    EntityManager manager;
    manager.AddEntity(2);
    manager.AddEntity(1);
    manager.AddEntity(4);
    manager.AddEntity(3);
    manager.ListAllEntities();
    return 0;
}
#包括
#包括
类实体{
公众:
int-num;
实体(int num):num(num){}
布尔运算符<(const-Entity&_-Entity)const{return(this->num<_-Entity.num);}
};
结构我的cmp{
布尔运算符()(常量实体*lhs,常量实体*rhs)常量{return(*lhs<*rhs);}
};
类实体管理器{
私人:
设置实体;
公众:
void AddEntity(int num){entities.insert(new Entity(num));}
void listalEntities()常量{
无符号整数i=0;
用于(自动和实体:实体){
标准::cout