From 13019c9e71b5d95183b7c056cfe7f811e325c0d1 Mon Sep 17 00:00:00 2001
From: Alex <enderice2@users.noreply.github.com>
Date: Fri, 28 Oct 2022 05:53:59 +0300
Subject: [PATCH] Added smart pointer header

---
 include/smartptr.hpp | 149 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 149 insertions(+)
 create mode 100644 include/smartptr.hpp

diff --git a/include/smartptr.hpp b/include/smartptr.hpp
new file mode 100644
index 0000000..10efc99
--- /dev/null
+++ b/include/smartptr.hpp
@@ -0,0 +1,149 @@
+#pragma once
+
+#include <debug.h>
+
+// show debug messages
+// #define DEBUG_SMARTPOINTERS 1
+
+#ifdef DEBUG_SMARTPOINTERS
+#define spdbg(m, ...) debug(m, ##__VA_ARGS__)
+#else
+#define spdbg(m, ...)
+#endif
+
+/**
+ * @brief A smart pointer class
+ *
+ * This class is a smart pointer class. It is used to manage the lifetime of
+ * objects. It is a reference counted pointer, so when the last reference to
+ * the object is removed, the object is deleted.
+ *
+ * Basic Usage:
+ * smart_ptr<char> pointer(new char());
+ * *pointer = 'a';
+ * printf("%c", *pointer); // Prints "a"
+ */
+template <class T>
+class smart_ptr
+{
+    T *RealPointer;
+
+public:
+    explicit smart_ptr(T *p = nullptr)
+    {
+        spdbg("Smart pointer created (%#lx)", RealPointer);
+        RealPointer = p;
+    }
+
+    ~smart_ptr()
+    {
+        spdbg("Smart pointer deleted (%#lx)", RealPointer);
+        delete (RealPointer);
+    }
+
+    T &operator*()
+    {
+        spdbg("Smart pointer dereferenced (%#lx)", RealPointer);
+        return *RealPointer;
+    }
+
+    T *operator->()
+    {
+        spdbg("Smart pointer dereferenced (%#lx)", RealPointer);
+        return RealPointer;
+    }
+};
+
+template <class T>
+class auto_ptr
+{
+};
+
+template <class T>
+class unique_ptr
+{
+};
+
+template <typename T>
+class shared_ptr
+{
+private:
+    class Counter
+    {
+    private:
+        unsigned int RefCount{};
+
+    public:
+        Counter() : RefCount(0){};
+        Counter(const Counter &) = delete;
+        Counter &operator=(const Counter &) = delete;
+        ~Counter() {}
+        void Reset() { RefCount = 0; }
+        unsigned int Get() { return RefCount; }
+        void operator++() { RefCount++; }
+        void operator++(int) { RefCount++; }
+        void operator--() { RefCount--; }
+        void operator--(int) { RefCount--; }
+    };
+
+    Counter *ReferenceCounter;
+    T *RealPointer;
+
+public:
+    explicit shared_ptr(T *Pointer = nullptr)
+    {
+        spdbg("Shared pointer created (%#lx)", RealPointer);
+        RealPointer = Pointer;
+        ReferenceCounter = new Counter();
+        if (Pointer)
+            (*ReferenceCounter)++;
+    }
+
+    shared_ptr(shared_ptr<T> &SPtr)
+    {
+        spdbg("Shared pointer copied (%#lx)", RealPointer);
+        RealPointer = SPtr.RealPointer;
+        ReferenceCounter = SPtr.ReferenceCounter;
+        (*ReferenceCounter)++;
+    }
+
+    ~shared_ptr()
+    {
+        spdbg("Shared pointer deleted (%#lx)", RealPointer);
+        (*ReferenceCounter)--;
+        if (ReferenceCounter->Get() == 0)
+        {
+            delete ReferenceCounter;
+            delete RealPointer;
+        }
+    }
+
+    unsigned int GetCount()
+    {
+        spdbg("Shared pointer count (%#lx)", RealPointer);
+        return ReferenceCounter->Get();
+    }
+
+    T *Get()
+    {
+        spdbg("Shared pointer get (%#lx)", RealPointer);
+        return RealPointer;
+    }
+
+    T &operator*()
+    {
+        spdbg("Shared pointer dereference (%#lx)", RealPointer);
+        return *RealPointer;
+    }
+
+    T *operator->()
+    {
+        spdbg("Shared pointer dereference (%#lx)", RealPointer);
+        return RealPointer;
+    }
+};
+
+template <class T>
+class weak_ptr
+{
+};