Printing std::strings produces no output - c++

Question

I was building a small template stack class for a side project and it appeared to be working correctly. However, when I tried it with strings it doesn't appear to work. I have no compilation errors or warnings. I simply get no output. I'm a little rusty in C++ but I wasn't expecting to get blocked by a problem that seems this simple.
My main function (for testing):
#include <iostream>
#include <fstream>
#include <string>
#include "myStack.h"
int main()
{
bool repeat = true;
int option = -1;
std::cout << "Option (1 - String | 2 - Integer) : ";
std::cin >> option;
std::cout << "\n";
switch (option)
{
case 1:
{
myStack<std::string> stringStack;
stringStack.push("!");
stringStack.push("there");
stringStack.push("Hello");
stringStack.show();
break;
}
case 2:
{
myStack<int> intStack;
intStack.push(3);
intStack.push(2);
intStack.push(1);
intStack.show();
break;
}
default:
break;
}
std::cout << "\n";
return 0;
}
Relevant parts of my stack class:
#pragma once
template <typename T>
class myStack
{
private:
T *elements;
size_t capacity;
public:
myStack();
T top();
size_t size();
void push(T pushed);
void pop();
bool isEmpty();
void show(std::ostream &out = std::cout);
};
template <typename T>
myStack<T>::myStack()
{
this->elements = NULL;
this->capacity = 0;
}
template <typename T>
void myStack<T>::push(T pushed)
{
this->elements = (T *)realloc(this->elements, (this->capacity + 1) * sizeof(T));
this->elements[this->capacity] = pushed;
this->capacity++;
}
template<typename T>
void myStack<T>::show(std::ostream &out)
{
for (int i = this->capacity - 1; i >= 0; i--)
{
out << this->elements[i] << std::endl;
}
}

Answer 1

Use of
this->elements = (T *)realloc(this->elements, (this->capacity + 1) * sizeof(T));
this->elements[this->capacity] = pushed;
to manage an array of std::strings is not right. Use of realloc to allocate memory is ok. However, it does not initialize the object properly. The second line is cause for undefined behavior since the object was not initialized properly.
If you are allowed to use std::vector, use it.
template <typename T>
class myStack
{
private:
std::vector<T> elements;
...
};
Then, use of capacity can be replaced by elements.size().
push can be simplified to:
template <typename T>
void myStack<T>::push(T pushed)
{
this->elements.push_back(pushed);
}
You'll have to update show() accordingly too.