将本地变量存储在STL容器中的类中是否安全？

Question

class MyMap : std::map<char, pro::image>
{
public:
     void MyMethod(char x);
     /** code **/
}

void MyMap::MyMethod(char x)
{
     pro::image my_img; // note that my_img is a local variable
     my_img.LoadFromFile("my_image.png");

     this->insert(std::pair<char, pro::image>(x, my_img)); // stored in the class
}

Now, is this code safe? Basically, does MyMap store a copy of my_img when I insert it, or does it store a reference ?

Answer 1

It will store a copy.

However, do you really need inheritance? You should make the std::map a class member.

class MyMap
{
    std::map<car, pro::image> map_;
public:
     void MyMethod(char x);
     /** code **/
};

void MyMap::MyMethod(char x)
{
     pro::image my_img; // note that my_img is a local variable
     my_img.LoadFromFile("my_image.png");

     map_.insert(std::pair<char, pro::image>(x, my_img)); // stored in the class
}