C++ Stack Implementation (array-based)

stack.cpp

#include <array>
#include <exception>
#include <iostream>


template <typename T>
class Stack {
public:
    T *stack_array_;
    int top_;
    int capacity_;

public:
    Stack(const int& size);
    ~Stack();

    bool isEmpty() {
        return top_ == -1;
    }
    bool isFull() {
        return top_ == capacity_ - 1;
    }

    void push(T value);
    T pop();
    T peek();
    void display();
    int size();
};

template <typename T>
Stack<T>::Stack(const int& size) {
    stack_array_ = new T[size];
    top_ = -1;
    capacity_ = size;
}

template <typename T>
Stack<T>::~Stack() {
    delete[] stack_array_;
    std::cout << "Stack deleted." << std::endl;
}

template <typename T>
void Stack<T>::push(T value) {
    if (!isFull()) {
        stack_array_[++top_] = value;
    } else {
        std::cout << "Stack is full." << std::endl;
    }
}

template <typename T>
T Stack<T>::pop() {
   if (!isEmpty()) {
       T value = stack_array_[top_];
       top_--;
       return value;
   } else {
       throw std::underflow_error("Stack is empty.");
   }
}

template <typename T>
T Stack<T>::peek() {
    if (!isEmpty()) {
        std::cout << "Current top element: "
            << stack_array_[top_] << std::endl;
        return stack_array_[top_];
    } else {
        throw std::underflow_error("Stack is empty.");
    }
}

template <typename T>
void Stack<T>::display() {
    if (!isEmpty()) {
        for (int i = 0; i <= top_; i++) {
            std::cout << stack_array_[i] << ' ';
        }
        std::cout << std::endl;
    } else {
        std::cout << "Stack is empty." << std::endl;
    }
}


template <typename T>
int Stack<T>::size() {
    if (!isEmpty()) {
        std::cout << "Current number of stack elements: "
            << top_ + 1 << std::endl;
        return top_ + 1;
    } else {
        std::cout << "Stack is empty." << std::endl;
        return 0;
    }
}


int main(){
    Stack<int> *stack = new Stack<int>(10);

    stack->push(5);
    stack->push(2);
    stack->push(5);
    stack->push(1);
    stack->push(3);
    stack->push(3);
    stack->push(2);
    stack->push(1);
    stack->push(1);
    stack->push(9);

    stack->display();               // 5 2 5 1 3 3 2 1 1 9
    stack->pop();
    stack->display();               // 5 2 5 1 3 3 2 1 1
    stack->peek();                  // Current top element: 1
    stack->size();                  // Current number of stack elements: 9
    stack->pop();
    stack->pop();
    stack->pop();
    stack->display();               // 5 2 5 1 3 3
    while (!stack->isEmpty()) {
        stack->pop();
    }
    stack->display();               // Stack is empty.
    delete stack;
}