why i get these warnings..

[transgalactic2]

warning C4047: 'function' : 'TreeNode *' differs in levels of indirection from 'TreeNode **__w64 '
warning C4024: 't' : different types for formal and actual parameter 1
warning C4028: formal parameter 1 different from declaration
??
and i descovered that if i use only one astrix in the signature and i pass
the pointer instead of &pointer

then it keeps the changes of the variables in the struct
if i say p->val=6 then it keeps it
but if i say p=NULL then it doesnt
i cant understand why
p->val is in the variable p
so it should get the same treatment as p
??

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define false 0
#define true 1


typedef struct TreeNode
{
	struct TreeNode *father;
	struct TreeNode *left;
	struct TreeNode *right;
	double val;
}TreeNode;
void t(TreeNode* g); 
int main()
{
   TreeNode* g;
   g=(TreeNode*)malloc(sizeof(TreeNode));
   g->val=6;
	t(&g);
	return 0;
}
void t(TreeNode** g)
{
  *g=NULL;
}

[EVOEx]

void t(TreeNode* g); 
[...]
void t(TreeNode** g)

See the problem yet?

[MK27]

It would seem to me that these do not match:

void t(TreeNode* g);
void t(TreeNode** g) {

Not sure why you want a pointer to pointer where a pointer would do, either.

[transgalactic2]

thanks

about my second problem
i descovered that if i use only one astrix in the signature and i pass
the pointer instead of &pointer

then it keeps the changes of the variables in the struct
if i say p->val=6 then it keeps it when we leave the function
but if i say p=NULL then it doesnt
i cant understand why
p->val is in the variable p
so it should get the same treatment as p
??

[MK27]

thanks

about my second problem
i descovered that if i use only one astrix in the signature and i pass
the pointer instead of &pointer

Yes, that's right. &pointer will work if the prototype included **. But for what you are doing, you don't need & or ** unless you want to declare the struct like this:

TreeNode g;   /* no asterisk, g is a struct */
t(&g);   /* address of struct = pointer */

instead of like this:

   TreeNode* g;
   g=(TreeNode*)malloc(sizeof(TreeNode));
   t(g);   /* no &, g is a pointer (to a struct) */