c++组合对象管理 - c++编程基础

有一些业务逻辑，需要管理多个同样类型的对象，并对外提供查询，删除等接口，在这些场合中，可以将被管理的对象称为Entity，管理Entity的类自然就叫做Entity_Manager，当以这样的方式组织层级对象时，很直观，而且项目的风格统一，每个人一旦熟悉了这种方式，理解别人写的Entity_Manager就很轻松。根据以往的项目经验，我自己实现了Entity和Entity_Manager类，代码如下：

#ifndef __ENTITY_H__  
#define __ENTITY_H__  
  
#include   
#include   
  
typedef unsigned int uint32;  
  
class Entity  
{  
protected:  
    Entity()  
    {  
        m_id = 0;  
    }  
  
public:  
    virtual ~Entity()  
    {  
    }  
  
    void id(uint32 _id)  
    {  
        m_id = _id;  
    }  
  
    uint32 id() const  
    {  
        return m_id;  
    }  
  
    void name(std::string _name)  
    {  
        m_name = _name;  
    }  
  
    std::string name() const  
    {  
        return m_name;  
    }  
      
private:  
    uint32 m_id;  
    std::string m_name;  
};  
  
//对所有子元素进行回调  
template  
class Entity_Exec  
{  
public:  
    Entity_Exec()  
    {  
    }  
  
    virtual ~Entity_Exec()  
    {  
    }  
  
    virtual bool exec(Concrete_Entity *entity) = 0;  
      
    virtual bool can_delete(Concrete_Entity *entity) const  
    {  
        return true;          
    }      
};  
  
class Guard_Ref  
{  
public:  
    Guard_Ref(bool &val) : m_val(val)  
    {  
        m_val = true;          
    }  
  
    ~Guard_Ref()  
    {  
        m_val = false;  
    }  
  
    bool &m_val;  
};  
  
template  
class Entity_Map  
{  
protected:  
    Entity_Map()  
    {  
        m_in_iteration = false;          
    }  
  
    ~Entity_Map()  
    {  
    }  
  
    //是否正在迭代中, 用于禁止在迭代map时进行删除迭代器等操作  
    bool in_iteration() const  
    {  
        return m_in_iteration;  
    }  
  
    bool add_entity(Key key, Entity *entity)  
    {  
        if(in_iteration())  
        {  
            return false;  
        }  
          
        if(m_entity_map.find(key) != m_entity_map.end())  
        {  
            return false;  
        }  
          
        m_entity_map[key] = entity;  
  
        return true;          
    }  
  
    Entity* get_entity(Key key) const  
    {  
        typename std::map::const_iterator iter = m_entity_map.find(key);  
  
        if(iter == m_entity_map.end())  
        {  
            return NULL;  
        }  
  
        return iter->second;  
    }  
  
    uint32 size() const  
    {  
        return m_entity_map.size();  
    }  
  
    bool empty() const  
    {  
        return m_entity_map.empty();  
    }  
  
    void clear()  
    {  
        if(!in_iteration())  
        {  
            m_entity_map.clear();  
        }          
    }  
  
    template  
    void exec_all(Entity_Exec &cb)  
    {  
        Guard_Ref guard(m_in_iteration);  
          
        for(typename std::map::iterator iter = m_entity_map.begin(); iter != m_entity_map.end(); ++iter)  
        {  
            cb.exec(static_cast(iter->second));              
        }  
    }  
  
    template  
    bool exec_until(Entity_Exec &cb)  
    {  
        Guard_Ref guard(m_in_iteration);  
          
        for(typename std::map::iterator iter = m_entity_map.begin(); iter != m_entity_map.end(); ++iter)  
        {  
            if(cb.exec(static_cast(iter->second)))  
            {  
                return true;                  
            }              
        }  
  
        return false;          
    }  
      
    template  
    bool exec_if(Entity_Exec &cb)  
    {  
        bool ret = false;  
        Guard_Ref guard(m_in_iteration);  
          
        for(typename std::map::iterator iter = m_entity_map.begin(); iter != m_entity_map.end(); ++iter)  
        {  
            Concrete_Entity *concrete_entity = static_cast(iter->second);  
  
            if(cb.exec(concrete_entity))  
            {  
                ret = true;  
            }  
        }  
          
        return ret;          
    }  
      
    void delete_entity(Key key)  
    {  
        if(!in_iteration())  
        {  
            m_entity_map.erase(key);  
        }          
    }  
      
    template  
    bool delete_if(Entity_Exec &cb, std::vector &del_vec)  
    {  
        if(in_iteration())  
        {  
            return false;  
        }  
  
        Guard_Ref guard(m_in_iteration);  
        bool ret = false;  
  
        for(typename std::map::iterator iter = m_entity_map.begin(); iter != m_entity_map.end(); ++iter)  
        {  
            Concrete_Entity *concrete_entity = static_cast(iter->second);  
              
            if(cb.can_delete(concrete_entity))  
            {  
                ret = true;                  
                del_vec.push_back

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