OwnVector使用方法请教

[likun123687]

作者你好 在学习你的代码过程中,有个代码问题有点疑问,OwnVector这个模板类的remove方法的不太清楚要怎么调用.

/** @brief vector of pointers, but accessed as values
 pointers pushed into OwnVector are owned by the vector,
 pointers will be auto deleted when it`s erased/removed from the vector
 or the vector is destroyed.
 Used with Composition Relationship.
*/
template<class T>
class OwnVector : public vector<Own<T>>
{
	typedef vector<Own<T>> OwnV;
public:
	using OwnV::OwnV;
	using OwnV::insert;

	bool remove(T* item)
	{
		auto it = std::remove(OwnV::begin(), OwnV::end(), item);
		if (it == OwnV::end()) return false;
		OwnV::erase(it);
		return true;
	}
	typename OwnV::iterator index(T* item)
	{
		return std::find(OwnV::begin(), OwnV::end(), item);
	}
	bool fast_remove(T* item)
	{
		size_t index = std::distance(OwnV::begin(), OwnVector::index(item));
		if (index < OwnV::size())
		{
			OwnV::at(index) = OwnV::back();
			OwnV::pop_back();
			return true;
		}
		return false;
	}
};

例子:

class demo{
public:
   demo(int i):num(i){
      cout<<"construct! " << i <<endl;
   }

   ~demo(){
      cout<<"class destruct! " << num <<endl;
   }
private:
   int num;
};


int main() {
    OwnVector<demo> ov;
    ov.push_back(New<demo>(1));
    ov.push_back(New<demo>(2));
    //ov.erase(ov.begin());
    //ov.remove();
    return 0;
}

比如这个例子中我想remove掉第一个item,应该怎么写呢?我在这个项目好像没有用到这个remove方法

[pigpigyyy]

抱歉，这个接口我没有做测试，这个原来模版接口的写法是不可用的……至少得改成这样你才能正常调用。

template<class T>
class OwnVector : public std::vector<Own<T>>
{
	typedef std::vector<Own<T>> OwnV;
public:
	using OwnV::OwnV;
	using OwnV::insert;

	bool remove(const Own<T>& item)
	{
		auto it = std::remove(OwnV::begin(), OwnV::end(), item);
		if (it == OwnV::end()) return false;
		OwnV::erase(it);
		return true;
	}
	typename OwnV::iterator index(const Own<T>& item)
	{
		return std::find(OwnV::begin(), OwnV::end(), item);
	}
	bool fast_remove(const Own<T>& item)
	{
		size_t index = std::distance(OwnV::begin(), OwnVector::index(item));
		if (index < OwnV::size())
		{
			OwnV::at(index) = OwnV::back();
			OwnV::pop_back();
			return true;
		}
		return false;
	}
};

调用代码是这样：

class demo{
public:
   demo(int i):num(i){
      cout<<"construct! " << i <<endl;
   }

   ~demo(){
      cout<<"class destruct! " << num <<endl;
   }
private:
   int num;
};


int main() {
    OwnVector<demo> ov;
    ov.push_back(New<demo>(1));
    ov.push_back(New<demo>(2));
    ov.remove(ov[0]);
    return 0;
}

这个类因为历史原因，是一个自己写的内存管理的容器，后来用标准库std::vector + std::unique_ptr做了替换，为了兼容临时改成这样。继承std标准库类的写法是不推荐的写法，因为自己很难保证自己写的子类也满足std的规范。后面会逐渐移除这些过渡代码。

[likun123687]

好的,谢谢作者答疑