Hello:

I have several memory problems (my program starts to consume wild amounts of memory) in one of my applications and I'm thinking that it is because I don't properly delete certain items like structures.

For example I've got a Structure A wich contains a QVector of reals and a QVector of pointers. I enter a function that returns a Structure B which only contains 1 Pointer and 1 Value. So I do somemething like

Qt Code: 
  1. StructB function(){
  2.      StructA a;
  3.      StructB b;
  4.      //Do stuff that initializes a and b
  5.     //In this stuff, there is a line that goes like b.pointer = a.vector[some_index];
  6.      return b;
  7. }
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How do I properly delete a? Or don't I have to?

Then I have a different situation. Where I have a PClass which is a parent class and two Descendants class calles ClassA and ClassB. Then I have a ClassC that uses all three in the following manner:

In ClassC.h there is a private variable declared like:
PClass *c;

In ClassC.cpp there is some code that says:
Qt Code: 
  1. switch (some_variable){
  2.     case 0:
  3.           c = new ClassA();
  4.     break;
  5.     case 1:
  6.           c = new ClassB();
  7.     break;
  8. }
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The user might then select something else. The ClassC object is NEVER destroyed until the end of the program. So if the user selects something else before the code above I wrote the following line:

delete c; //After this comes the switch.

Is this the right way to resolve this? Also Both Classes B and A have an extensive ammount of QVectors... Should I destroy (using QVector::clear() command) all the vectors in the Classe's Destructor?

Thanks for any help.