Create unique pointer impl

Author: XuhuaHuang

Pointer/unique_ptr.hpp

@@ -0,0 +1,60 @@
+#include <memory>
+#include <utility> // std::exchange
+
+template <typename T, typename Deleter = std::default_delete<T>>
+class unique_ptr {
+private:
+  T*      ptr;
+  Deleter deleter;
+
+public:
+  // Constructors
+  explicit unique_ptr(T* p = nullptr) noexcept
+    : ptr(p) {}
+
+  // Destructor
+  ~unique_ptr() {
+    if (ptr) {
+      deleter(ptr);
+    }
+  }
+
+  // Delete copy semantics
+  unique_ptr(const unique_ptr&)            = delete;
+  unique_ptr& operator=(const unique_ptr&) = delete;
+
+  // Move constructor
+  unique_ptr(unique_ptr&& other) noexcept
+    : ptr(std::exchange(other.ptr, nullptr)) {}
+
+  // Move assignment
+  unique_ptr& operator=(unique_ptr&& other) noexcept {
+    if (this != &other) {
+      delete ptr; // clean up current resource
+      ptr = std::exchange(other.ptr, nullptr);
+    }
+    return *this;
+  }
+
+  // Observers
+  T* get() const noexcept { return ptr; }
+
+  T& operator*() const noexcept { return *ptr; }
+
+  T* operator->() const noexcept { return ptr; }
+
+  explicit operator bool() const noexcept { return ptr != nullptr; }
+
+  // Modifiers
+  T* release() noexcept { return std::exchange(ptr, nullptr); }
+
+  void reset(T* p = nullptr) noexcept {
+    delete ptr;
+    ptr = p;
+  }
+};
+
+template <typename T, typename... Args>
+unique_ptr<T> make_unique(Args&&... args) {
+  return unique_ptr<T>(new T(std::forward<Args>(args)...));
+}