C++ Error in ' ' : free(): invalid pointer - c++

Question

I've read through similar problems, but I can't find anything that specifically addresses my problem (or I simply don't understand the other solutions)
I am trying to implement a template Stack class, and am having an issue when trying to push to the stack. here is my Stack.cpp:
#ifndef _STACK_H
#define _STACK_H
#include <string>
#include <stdio.h>
#include "Node.cpp"
template<typename T>
class Stack{
private:
Node<T>* mHead;
public:
Stack();
~Stack();
void push(T data);
};
template<typename T>
Stack<T>::Stack(){
mHead = NULL;
}
template<typename T>
Stack<T>::~Stack(){
delete mHead;
}
template<typename T>
void Stack<T>::push(T data){ // <-- having trouble with this method
Node<T>* temp = new Node<T>;
temp->data = data;
//if head is already empty, just create 1 Node
if(mHead==NULL){
printf("if working\n");
mHead = temp;
}else{
printf("else working\n");
//rearrange Nodes
temp->next = mHead;
mHead = temp;
}
printf("success\n");
}
#endif
push() gets called from a function in the manager class:
void Manager::testPush(){
Stack<int> test;
int number = 3;
test.push(3);
}
When I run the code and call managers testPush() method, i get the following being printed:
if working
success
*** Error in `./assignment': free(): invalid pointer: 0x0000000000f11078 ***
[1] 14976 abort (core dumped) ./assignment
I'm not sure what free() means, and what could possibly be causing this error/abort

Answer 1

It seems that you forgot to set data member next to NULL in node temp.
template<typename T>
void Stack<T>::push(T data){ // <-- having trouble with this method
Node<T>* temp = new Node<T>;
temp->data = data;
temp->next = NULL; // <=== add this statement
//if head is already empty, just create 1 Node
if(mHead==NULL){
printf("if working\n");
mHead = temp;
If the class Node has a constructor with two parameters or if it is an aggregate you could write simpler
template<typename T>
void Stack<T>::push( const T &data )
{
mHead = new Node<T> { data, mHead };
}
Take into account that the destructor of class Node must delete all nodes in the stack.
This function
void Manager::testPush(){
Stack<int> test;
int number = 3;
test.push(3);
}
also looks questionably because test is a local variable of the function. The stack can be used only inside the function.