How to make a short form of copy constructor in the inherited class?

[lucky6969b]

let's say I have a base class called A, and a derived class B which is derived from A
and B has a copy constructor to A,
This copy constructor has to initialize every property in A
Let's say A has tons of properites, and in the copy constructor of B
I have to type in all the properties which is quite time-consuming.
I wonder if there are any short form to copy construct an object of B which
has a base class of A?

Thanks in advance
Jack

[laserlight]

Perhaps you should break A up into smaller classes that models one thing and models it well?

[2kaud]

Perhaps you could give an example.

[monarch_dodra]

This copy constructor has to initialize every property in A.

No, that's wrong. That's A's (copy) constructor's job. By the time B's copy constructor is running, A is fully built and initialized. B cannot initialize A's fields.

The only thing B's copy constructor has the freedom of doing is indicating which constructor for A it wants run.

I wonder if there are any short form to copy construct an object of B which
has a base class of A

Just call A's copy constructor before running B's constructor:

class A {
  private:
    T t;

  public:
    A(const A& a) : t(a.t) {}
};

class B : public A {
  public:
    B(const B& b) : A(b) {}
};

Again, A *must* have a constructor. If you omit which constructor you want, it will call the default constructor (if available). What you want to do is not possible if A does not provide an adequate constructor.

B has a copy constructor to A

That's not a copy constructor. It's just a constructor.

[2kaud]

If the classes need copy constructors then they will also need move constructors and copy/move assignments.