need help assigning one structure to another using pointers

Hi,
i have two pointer to structures named *currMB and *PrevMB and i want to assign PrevMB into currMB.
will the C++ code below work.

struct Macroblock *currMB;
struct Macroblock *PrevMB;

*currMB= & PrevMB;

and if i want to average these two structures and put the output in currMB.

then can i write

currMB = (currMB+PrevMB)/2;

No, it will fail (crash)
You must instantiate Macroblock objects, not just the pointers that point to none/nowhere.

Quote:

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Originally Posted by naeem561

Hi,
i have two pointer to structures named *currMB and *PrevMB and i want to assign PrevMB into currMB.
will the C++ code below work.

struct Macroblock *currMB;
struct Macroblock *PrevMB;

*currMB= & PrevMB;

and if i want to average these two structures and put the output in currMB.

then can i write

currMB = (currMB+PrevMB)/2;

---

How do you average a struct? Conceptually that doesn't make much sense.

As victor said, they are only pointers currently pointing to nothing.

Code:

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struct Macroblock *currMB = new Macroblock;
struct Macroblock *PrevMB = new Macroblock;

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Now they point to a Macroblock (don't forget to delete them as soon as you are done with them).

Code:

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currMB = (currMB+PrevMB)/2;

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To do this you need to implement your own = + and / operator. Assuming that your struct contains some numbers you can average.

Well.. the program will not compile itself!
You cannot add two pointers.