call to pure virtual function from base class constructor

Question

I have a base class MyBase that contains a pure virtual function:

void PrintStartMessage() = 0

I want each derived class to call it in their co

Answer 1

Trying to call a pure abstract method from a derived while that object is still being constructed is unsafe. It's like trying to fill gas into a car but that car is still on the assembly line and the gas tank hasn't been put in yet.

The closest you can get to doing something like that is to fully construct your object first and then calling the method after:

template 
T construct_and_print()
{
  T obj;
  obj.PrintStartMessage();

  return obj;
}

int main()
{
    Derived derived = construct_and_print();
}