invalid conversion What's this?

I was on a middle on making my code then I encountered this

Code:

#include<stdio.h>
#include<stdlib.h>
#include<conio.h>

struct stackNode
{
       int data;
       struct stackNode *nextPtr;
       };
       
      typedef struct stackNode StackNode;
      typedef StackNode *StackNodePtr;
      
      
void instructions();
void push(StackNodePtr *, int);
            
            
int main()
{
    instructions();
    
    getch();
    }


  void instructions()
  {
       printf("Please enter a choice\n");
       printf("[1]Push a value on the stack\n");
       printf("[2]Pop a value off the stack\n");
       printf("[3]Display the whole stack\n");
       printf("[4]Exit");
       } 
     
     void push (StackNodePtr *topPtr, int info)
     {
          StackNodePtr newPtr;
          newPtr = malloc(sizeof (StackNode));
          if(newPtr !=NULL)
          {
                    newPtr->data=info;
                    newPtr->nextPtr=*topPtr;
                    *topPtr = newPtr;
                    }
          }

I am not yet but when I compiled it there's an error popping it help please

on which line?

newPtr = malloc(sizeof (StackNode)); this one :|

malloc returns a void pointer. You need to typecast it.

newPtr =(StackNode *) malloc(sizeof
(StackNode));

i think this should work.

Make sure you are using C compiler. Not c++.
And don't cast malloc return value in C.
http://c-faq.com/malloc/mallocnocast.html

If your compiler is complaining about an invalid conversion (or words to that effect) then it is a C++ compiler.

In C++, unlike C, a void pointer cannot be implicitly converted to another pointer type. You will therefore need to either tweak your compiler to compile as C (how you do that, if it is possible, is compiler specific) or use an explicit conversion to stop the compiler moaning.

Code:

   newPtr = (StackNodePtr)malloc(sizeof(StackNode));

I am using a bloodshed C++

btw before i forget can anyone translate this without typedef?