Why Can't I Use References as Elements in a Standard Vector?

Why Won't My Vector Accept References?

Problem: Vector works, but Vector causes compiler errors.

Explanation:

Vectors and other containers require their component types to be assignable. A reference is a non-assignable type because it holds a constant reference to a specific memory location. Once a reference is initialized, it cannot point to a different object.

Possible Approaches:

• Use Pointers Instead: This is the recommended option if you need to hold multiple references to different objects. Pointers can be assigned and reassigned to different memory locations.

std::vector<int*> hello;

• Create a Vector of References to Objects of a Fixed Type: This approach is acceptable if all the references refer to objects of the same type that will not be assigned or modified after insertion into the vector.

struct MyStruct { int data; };

std::vector<MyStruct&> hello;

However, it's important to note that this strategy can lead to dangling references if the referenced objects are deleted or moved.

• Use a Wrapper Class: You can create a wrapper class that holds a reference internally and provides an assignable interface. This allows you to use the class as a container element.

class Wrapper {
protected:
    int& _data;
public:
    Wrapper(int& data) : _data(data) {}
};

std::vector<Wrapper> hello;

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