Pointer to an array of pointers to nodes

Question

With this struct

typedef struct tNode_t {
    struct tNode_t **a;
} tNode;

I want to be able to have a point to an array to 5 pointers to tNodes

example main:

int main()
{
    tNode t;
    tNode (*alpha)[5];
    t.a = alpha;
}

why doesn't this work?

Answer 1

This defines a pointer to an array of tNodes:

tNode (*alpha)[5];

This defines an array of pointers to tNodes:

tNode *alpha[5];

Answer 2

In your code alpha and a are pointers to very different objects. And since both are pointers, as you correctly defined them, no decaying will take place . Only arrays decay so alpha can't simply decay to another pointer type.

And why are they so different ? When you increment a, it will point to the next struct tNode_t * . When you increment alpha it will point 5 struct tNode * further.