C++ class const member intialization within constructor body

Question

I have a problem with initialization of a const class member. I have to do many calculations before initialization of the const member, so I can't use this syntax

Class::Class(int value) : value(value) {}

I wish to initialize the member in the constructor body, for example:

Class::Class(int value) {
  if (Function1(value)) {
    this->value = value;
    Function2(&this->value);
  }
  else
    this->value = value * 2;
}

Is it possible? Hope for your help!

Answer 1

Collect all the calculation into a static calculation function.

struct Class {
    static int calcValue(int value) {
        if (Function1(value) {
            Function2(&value);
            return value;
        }
        return value * 2;
    }

    Class(int val)
        : value(calcValue(val))
    {}
};