Hello to everyone, and happy new year.
This is my first post to this list, and I am not very sure if this is the
correct place to post my question. Anyway..
I am starting to program using STL and found something strange in the
vector<> implementation. Every time I call push_back to add a new object, the
container call the destructor for the previous (if any) object.
I had make this code to test and comprove:
****** CODE ******
#include <iostream>
#include <vector>
using namespace std;
class Dummy {
public:
Dummy(int value){
mValue = value;
cout << "Dummy value " << mValue << " created at address: " << (int)
this << endl;
};
~Dummy(){
cout << "Dummy value " << mValue << " deleted from address: " << (int)
this << endl;
};
void Set(int value){
mValue = value;
cout << "Dummy value " << mValue << " set in address: " << (int)
this << endl;
};
private:
int mValue;
};
main(){
vector<Dummy> MyVector;
Dummy MyDummy(0);
int x;
for (x=0; x<5; x++){
MyDummy.Set(x);
cout << "Push Back..." << endl;
MyVector.push_back(MyDummy);
}
cout << "This is the End" << endl;
};
****** END OF CODE ******
when i run this piece, i got:
****** CONSOLE OUTPUT *******
Dummy value 0 created at address: -1073744480 (this is OK)
Dummy value 0 set in address: -1073744480 (OK)
Push Back...
Dummy value 1 set in address: -1073744480 (OK)
Push Back...
Dummy value 0 deleted from address: 134524936 (I cant understand why this)
Dummy value 2 set in address: -1073744480
Push Back...
Dummy value 0 deleted from address: 134524944
Dummy value 1 deleted from address: 134524948
Dummy value 3 set in address: -1073744480
Push Back...
Dummy value 4 set in address: -1073744480
Push Back...
Dummy value 0 deleted from address: 134525096
Dummy value 1 deleted from address: 134525100
Dummy value 2 deleted from address: 134525104
Dummy value 3 deleted from address: 134525108
This is the End
Dummy value 4 deleted from address: -1073744480
Dummy value 0 deleted from address: 134525264
Dummy value 1 deleted from address: 134525268
Dummy value 2 deleted from address: 134525272
Dummy value 3 deleted from address: 134525276
Dummy value 4 deleted from address: 134525280
****** END OF CONSOLE OUTPUT *******
I think that the destructor ~Dummy() should be used to clean up some stuff in
the class before deleting all pointers. So I cant understand why it gets
called for the previous last item when i call push_back.
I had compiled the above code with gcc 3.4 and 3.3, and get the same results,
so I wonder if is my fault.
I ask to someone tell me what i am doing wrong, or point me to some solution.
Thanks in advice.
