Thread: help, throwing exception from constructor

hi I'm learning c++ from a book, know im on exception handling, but the book do not explain how to deal with exceptions when an error happens while creating an object, how i deal with this? heres my idea but dont works

Code:

class Car{
         public:
              Car(int speed){
                     cout << "constructor called";
                     if(speed > 500)
                       throw speed; 
             }
             
            //I need to catch the exception and call the destructor
            //any idea?
            catch(int spd){
                cout << "at " << spd " you'r travelinig too fast";
            } 
            ~Car(){
                     cout << "Destructor called";
             }
};

int main{
    Car toyota(1500);
   //error because 1500 is too fast, so destructor must be called     
   //here, or in other words object must be destroyed.
    ....
   //code continues with object toyota already destroyed
   
   return 0;
}

//im attaking this problem fine or not? how i do it?
//the books says !when u throw an exception from a constructor..
//the destructor is called" but this is not working to me"

thanks for any help , and please excuse my poor english

I don't believe it does. At any rate, when I have something in a constructor that may fail, I usually put it into a separate initialization function, and then make a static builder. Ex:

Code:

class Car
{
public:
   static Car* buildCar(int speed)
   {
      Car* car = new Car( );
      bool success = car->init( );
      if (!success)
      {
         delete car;
         car = 0; // Set pointer to NULL.
      }
      return car;
   }

   ~Car( ) { }
private:
   Car( ) { }

   bool init(int sp)
   {
      if(sp > 500)
         return false;
      speed = sp;
      return true;
   }

   int speed;
};

good zach, thanks a lot for the code

whoa thats why :-)

thanks stoned
so all the variables i created whit the "new" in the constructor will be cleaned from memory too?