如何在C ++中存储和添加指向引用向量的链接？

Question

I have a situation in which I have an object of Class1 and a vector of objects of Class2. My goal is to have the object of Class1 contain references to certain objects in the vector of Class2. Class1 contains the members:

std::vector<Class2&> links;

void addLink(Class2 &obj)
{
  links.push_back(obj)
}

I then want to iterate through the objects of Class2 and for any objects which meet a certain condition, I want to add a link like so:

for (std::vector<Class2&>::iterator i = vector2.begin(); i != vector2.end(); ++i)
{
  if (condition_satisfied(*i))
  {
    obj1.addLink(*i)
  }
}

However, doing this gives me compile-time errors of C2528: pointer to reference is illegal. What am I doing wrong here?

Answer 1

std::vector<T> requires T to be CopyAssignable in C++98, Eraseable in C++11, but a plain reference is neither. In other words, references cannot be stored in std::vector .

You may like to use plain pointers instead. Or std::reference_wrapper<T> , which is a pointer in disguise.