Implement stack using linked list

Author: XuhuaHuang

include/ds/stack.hpp

@@ -0,0 +1,75 @@
+#pragma once
+#ifndef DS_STACK_HPP
+#define DS_STACK_HPP
+
+#include <cstddef>
+#include <stdexcept>
+#include <utility>
+
+namespace ds {
+
+template <typename value_t>
+class stack_t {
+private:
+  struct node_t {
+    value_t value;
+    node_t* next;
+
+    template <typename... args_t>
+    node_t(node_t* next_node, args_t&&... args)
+      : value(std::forward<args_t>(args)...)
+      , next(next_node) {}
+  };
+
+  node_t*     head = nullptr;
+  std::size_t size = 0;
+
+public:
+  stack_t() = default;
+
+  ~stack_t() {
+    while (head) {
+      auto* next = head->next;
+      delete head;
+      head = next;
+    }
+  }
+
+  template <typename... args_t>
+  void push(args_t&&... args) {
+    head = new node_t(head, std::forward<args_t>(args)...);
+    ++size;
+  }
+
+  void pop() {
+    if (empty()) {
+      throw std::runtime_error("stack is empty");
+    }
+    auto* next = head->next;
+    delete head;
+    head = next;
+    --size;
+  }
+
+  value_t& top() {
+    if (empty()) {
+      throw std::runtime_error("stack is empty");
+    }
+    return head->value;
+  }
+
+  const value_t& top() const {
+    if (empty()) {
+      throw std::runtime_error("stack is empty");
+    }
+    return head->value;
+  }
+
+  bool empty() const noexcept { return size == 0; }
+
+  std::size_t get_size() const noexcept { return size; }
+};
+
+} // namespace ds
+
+#endif // !DS_STACK_HPP