Temporary object returns

[xeyide]

What is the difference between using the a "temporary object" and creating a new object on a local scope?

For example, lets say we have an Object with two int data members, and a member function called foo. What is the difference between :

// ex 1.
Object Object::foo( void ) {
    Object temp( 1, 2 );

    return temp;
}

and

// ex 2
Object Object:foo( void ) {

   return Object( 1, 2 );

}

As I understand it: in ex 1, an object is created in dynamic memory and given the name temp. It's assigns the data members to 4 and 7 according to the constructors.
return does it's work.

in ex 2 seems like it's doing the same with with out assigning it a name?

[helios]

dynamic memory

No, that's stack memory. Dynamic (or heap) memory would be
Object *temp=new Object(1,2);

Both functions are equivalent in this case.

[m4ster r0shi]

Both functions are equivalent in this case.

helios is right. Your functions both use stack allocation. Check this out, it demonstrates that heap (dynamic) memory allocation takes place in a different place than stack allocation. It also demonstrates that your two functions use the same allocation method.

#include <iostream>
using namespace std;

class Object
{
      public:
      Object(){cout << "creating   Object at " << this << endl;}
      ~Object(){cout << "destroying Object at " << this << endl;}
};

Object f1_stack()
{
       Object object;
       return object;
}

Object f2_stack()
{
       return Object();
}

Object * f1_heap()
{
       Object * object=new Object();
       return object;
}

Object * f2_heap()
{
       return new Object();
}

int main()
{
    //stack allocation
    f1_stack();
    f2_stack(); //same place as f1_stack()
    
    //heap allocation
    delete f1_heap();
    delete f2_heap(); //same place as f1_heap()

    cin.get();
    return 0;
}

Try removing one or both delete operators to see what happens ;)

[screw]

Some discussing about returning an object:

http://stackoverflow.com/questions/204396/returning-objects-in-c

http://www.informit.com/articles/article.aspx?p=25033&seqNum=3