Error 0xC0000005 with a simple code wtf?

[ihato]

class ImOk{
   public:
   int x,y;
};
class Dude{
    public:
    ImOk* t;
    Dude(ImOk &T){
        cout<<"Ok";
        *t = T;
        cout<<"NotOk";
    }
};
ImOk mk;
int main(){
   Dude dude(mk);
   return 0;
}

And then I get the error:

Process returned -1073741819 (0xC0000005)   execution time : 14.521 s
Press any key to continue.

Also, only "Ok" is printed, but not "NotOk".

So. what's wrong???????


I use Code::Blocks IDE.

[Chervil]

ImOk* t;
t is an uninitialised pointer. It could contain any random address.

Therefore *t = T; this assignment is updating the memory location pointed to by that same pointer. This is the cause of the error.

You could fix this by putting
t = new ImOk;
before attempting to use the pointer.

If you do so, there should be a corresponding delete t; in the destructor of class Dude.

Alternatively, you could put t = &T; instead of *t = T;
In this case, the pointer t instead of pointing to its own independent object, is pointing to the parameter T, which in turn represents the object named mk.

[Disch]

Really... you don't need (and shouldn't use) pointers here at all. Just change 't' to be an object instead of a pointer.

class Dude{
    public:
    ImOk t;  // <- no need for a pointer
    Dude(ImOk &T){
        cout<<"Ok";
        t = T;  // <- this is fine
        cout<<"NotOk";
    }

[ihato]

Alright I understand now. just changed to t=&T; and it's fine now. thanks :)

I had to use pointers because I wanted to change passed ImOk directly.
tnx again.