Question

Is this possible? For example if i write

Car myCar;

Then the constructor taking no arguments of Car is called. It results in an error if there is only a constructor taking arguments.

In Java I can easily declare an object and create it later using the exact same statement as above.

Answer 1

No, this is not possible. You could come up with some dirty hacks based on placement new which may get you close, but I doubt you are interested in them.

Why do you want to do that? Perhaps there is some clean way how to achieve that in a C++ style.

If you only want to create a variable which will point to some object later, this is what pointers are used for in C++.

auto_ptr<Car> car;

car = new Car(xxx);

Or “old way”:

Car *car = NULL;

car = new Car(xxx);

delete car;

To find an item in a vector a code like this is commonly used:

std::vector <Car> cars;
Car *find = NULL;
for(std::vector<Car>::iterator car = cars.begin(); car != cars.end(); ++car )
for (int i=0; i<cars.size(); i++)
  if (Match(*car,xxx)
  {
    find=car;
    break;
  }

In many situations you would probably also prefer not to have a vector of cars, but of pointers to cars as well.