Thread: remove warning message multi dimensional pointers

Why doesn't that terminology work?

Originally Posted by Click_here

I'm proposing that by forcing the programmer to dereference a pointer to get its value, you are reminding everyone that it is a pointer. Isn't that a good thing?

And indeed multip[i][j] dereferences the pointer named multip. The point here is that the conversion of an array to a pointer to its first element is canonical in C. Trying to avoid that by passing a pointer to the array rather than the array itself (and hence a pointer to its first element) is unusual and complicates the syntax unnecessarily.

If you really want to avoid this, then I would say that the proper thing to do is to encapsulate the 2D array in a struct:

Code:

struct click_here_type
{
    int x[5][5];
};

void click_here_print_element(const struct click_here_type *click_here, size_t i, size_t j)
{
    printf("%d", click_here->x[i][j]);
}

/* ... */
click_here_type click_here;
/* ... */
click_here_print_element(&click_here, 1, 1);

Originally Posted by Click_here

What are the disadvantages of treating a pointer to a 2D array like a pointer to a 2D array?

There are no disadvantages in doing that. Rather, the disadvantage is in having a pointer to a 2D array when a pointer to a 1D array will suffice.

Originally Posted by laserlight

Rather, the disadvantage is in having a pointer to a 2D array when a pointer to a 1D array will suffice.

Just for completeness - Can you think of an advantage to using a pointer to a 2D array?

Originally Posted by Click_here

Can you think of an advantage to using a pointer to a 2D array?

Sure, e.g., to iterate over the elements of a 3D array.

Originally Posted by laserlight

Sure, e.g., to iterate over the elements of a 3D array.

A good sense of humour is not lost on me :P

Originally Posted by Barney McGrew

Well, with that terminology you call the following three types the same thing.

Code:

char (*)[3][1];
int (*)[4][2];
int (*)[5][2];

A pointer to a 2D array?

Originally Posted by Click_here

A pointer to a 2D array?

Also, I think that that is fine - Because we are not discussing the size of the 2D arrays, nor the data type.

What we are discussing is whether using a pointer to a 2D array has any advantages over a pointer to a 1D array.

Originally Posted by Barney McGrew

I don't see how it's helpful to talk about imaginary types.

What do you mean by that?

Originally Posted by Barney McGrew

I don't see how it's helpful to talk about imaginary types.

Do you mean that a conversation about an int will differ from a char?

Originally Posted by Barney McGrew

I find it's less confusing to describe specific types rather than certain characteristics of types.

Fair enough.