在范围内创建新对象并退出时会发生什么

Question

If you create an object of any class inside a function and you push it into a vector, when you exit that function what happens to the object? It gets destroyed? If yes why? It shouldn't since we have a vector referring that object that will be used later in the code...

void class::foo(){
  //this class object has a private vector called 've'
  ve.push_back(aNotherClass(somearg));
  //watever
}//exit
void class::foo2(){
  aNotherClass an = ve.pop_back(); //example code not sure if it works.
  cout << an.getSomeAtrribute() << endl;
  //will print like 432042 something like this and I'm sure it is not that value. is it '->' or '.' ?
}

Answer 1

vector.push_back makes a copy of the argument. The local object you created will be destroyed, but the vector will retain a copy. However, if that copy is just a copy of a pointer then you're in trouble.

Answer 2

The local object created on stack (without using the new operator) will be destroyed. It is the language specification.

From the other side, the vector can be implemented in a way that it will create its own copy of an object. Thus allowing you to keep the data event after exit from the function.