feat: C++ implementation of unique_ptr

Studio/Studio/SharedPtr.h

@@ -92,26 +92,55 @@ private:                  //
     mutex* _pMutex;       // 计数自增非原子操作，加锁解决多线程
 };
 
-int main()
+//int main()
-{
+//{
-    SharedPtr<int> sp1(new int(10));
+//    SharedPtr<int> sp1(new int(10));
-    SharedPtr<int> sp2(sp1);
+//    SharedPtr<int> sp2(sp1);
-    *sp2 = 20;
+//    *sp2 = 20;
-                                                                //sp1 与 sp2 在管理这部分资源，引用计数为 2
+//                                                                //sp1 与 sp2 在管理这部分资源，引用计数为 2
-    cout << sp1.useCount() << "  *ptr:" << *sp1 << endl;		//2	 20
+//    cout << sp1.useCount() << "  *ptr:" << *sp1 << endl;		//2	 20
-    cout << sp2.useCount() << "  *ptr:" << *sp2 << endl;		//2	 20
+//    cout << sp2.useCount() << "  *ptr:" << *sp2 << endl;		//2	 20
+//                                                                  
+//    SharedPtr<int> sp3(new int(30));                              
+//    sp2 = sp3;		                                            //sp3 赋值给它，释放管理的旧资源，引用计数-1，   
+//    cout << sp1.useCount() << "  *ptr:" << *sp1 << endl;        //1	 20
+//    cout << sp2.useCount() << "  *ptr:" << *sp2 << endl;        //2	 30
+//    cout << sp3.useCount() << "  *ptr:" << *sp3 << endl;        //2	 30
+//                                                                  
+//    sp1 = sp3;                                                    
+//    cout << sp1.useCount() << "  *ptr:" << *sp1 << endl;        //3	 30
+//    cout << sp2.useCount() << "  *ptr:" << *sp2 << endl;        //3	 30
+//    cout << sp3.useCount() << "  *ptr:" << *sp3 << endl;        //3	 30
+//
+//    std::cout << "Hello World!\n";
+//    return 0;
+//}
 
-    SharedPtr<int> sp3(new int(30));                              
+/*******************************************************************
-    sp2 = sp3;		                                            //sp3 赋值给它，释放管理的旧资源，引用计数-1，   
+ * 打印结果:
-    cout << sp1.useCount() << "  *ptr:" << *sp1 << endl;        //1	 20
+ * no default constructor
-    cout << sp2.useCount() << "  *ptr:" << *sp2 << endl;        //2	 30
+ * copy constructor
-    cout << sp3.useCount() << "  *ptr:" << *sp3 << endl;        //2	 30
+ * addRefCount
-                                                                  
+ * 2  *ptr:20
-    sp1 = sp3;                                                    
+ * 2  *ptr:20
-    cout << sp1.useCount() << "  *ptr:" << *sp1 << endl;        //3	 30
+ * no default constructor
-    cout << sp2.useCount() << "  *ptr:" << *sp2 << endl;        //3	 30
+ * copy assignment constructor
-    cout << sp3.useCount() << "  *ptr:" << *sp3 << endl;        //3	 30
+ * release
-
+ * addRefCount
-    std::cout << "Hello World!\n";
+ * 1  *ptr:20
-    return 0;
+ * 2  *ptr:30
-}
+ * 2  *ptr:30
+ * copy assignment constructor
+ * release
+ * addRefCount
+ * 3  *ptr:30
+ * 3  *ptr:30
+ * 3  *ptr:30
+ * Hello World!
+ * destructor
+ * release
+ * destructor
+ * release
+ * destructor
+ * release
+ ******************************************************************/

Studio/Studio/Studio.cpp

@@ -7,14 +7,3 @@
 //{
 //    std::cout << "Hello World!\n";
 //}
-
-// Run program: Ctrl + F5 or Debug > Start Without Debugging menu
-// Debug program: F5 or Debug > Start Debugging menu
-
-// Tips for Getting Started: 
-//   1. Use the Solution Explorer window to add/manage files
-//   2. Use the Team Explorer window to connect to source control
-//   3. Use the Output window to see build output and other messages
-//   4. Use the Error List window to view errors
-//   5. Go to Project > Add New Item to create new code files, or Project > Add Existing Item to add existing code files to the project
-//   6. In the future, to open this project again, go to File > Open > Project and select the .sln file

Studio/Studio/Studio.vcxproj

@@ -141,11 +141,13 @@
   <ItemGroup>
     <ClCompile Include="SharedPtr.cpp" />
     <ClCompile Include="Studio.cpp" />
+    <ClCompile Include="UniquePtr.cpp" />
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="MemoryAlignment.h" />
     <ClInclude Include="SharedPtr.h" />
     <ClInclude Include="SpecialMembers.h" />
+    <ClInclude Include="UniquePtr.h" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">

Studio/Studio/Studio.vcxproj.filters

@@ -21,6 +21,9 @@
     <ClCompile Include="SharedPtr.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="UniquePtr.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="MemoryAlignment.h">
@@ -32,5 +35,8 @@
     <ClInclude Include="SharedPtr.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="UniquePtr.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>

Studio/Studio/UniquePtr.cpp

@@ -0,0 +1 @@
+#include "UniquePtr.h"

Studio/Studio/UniquePtr.h

@@ -0,0 +1,125 @@
+/*******************************************************************
+ * Copyright (c) 2022~2023 XMuli  All rights reserved.
+ * GitHub: https://github.com/XMuli
+ * Description: C++ 实现一个核心的 unique_ptr 智能指针模板类；
+ * Ref: https://www.jianshu.com/p/77c2988be336
+ *		https://juejin.cn/post/7122641980315680782
+ *		https://juejin.cn/post/7099967913594978341
+ ******************************************************************/
+
+#pragma once
+#include <iostream>
+using namespace std;
+
+template <typename T>
+class UniquePtr
+{
+public:
+	constexpr UniquePtr() : _ptr(nullptr) { cout << "default constructor" << endl; };
+	explicit  UniquePtr(T* obj) : _ptr(obj) { cout << "no default constructor" << endl; };
+
+	UniquePtr(UniquePtr<T>&& obj) noexcept 
+		: _ptr(obj._ptr) 
+	{
+		cout << "move constructor" << endl;
+		obj._ptr = nullptr;
+	}
+	UniquePtr<T>& operator=(UniquePtr<T>&& obj) noexcept
+	{
+		cout << "move assignment constructor" << endl;
+		if (&obj != this) {
+			if (obj._ptr) {
+                _ptr = obj._ptr;
+                obj._ptr = nullptr;
+			}
+		}
+
+		return *this;
+	}
+
+	UniquePtr(const UniquePtr<T>& obj) = delete;		// C++11 delete 禁止方式，C++98 用 private 来隐藏
+    UniquePtr<T>& operator=(const UniquePtr<T>& obj) = delete;
+
+	~UniquePtr()
+	{
+		cout << "destructor" << endl;
+		if (_ptr) {
+			delete _ptr;
+			_ptr = nullptr;
+		}
+	}
+
+	T& operator*() const { return *_ptr; }
+	T* operator->() const { return _ptr; }
+	T* get() const { return _ptr; }
+
+	T* release()            // return std::exchange(_ptr, nullptr); // C++14
+	{
+		T* temp = _ptr;
+        _ptr = nullptr;
+		return temp;
+	}
+
+	void reset(T* ptr)		// std::exchange(_ptr, ptr); // C++14
+	{
+		_ptr = ptr;
+	}
+
+	void swap(UniquePtr<T>& obj)
+	{
+		std::swap(_ptr, obj._ptr);
+	}
+
+private:
+	T* _ptr;
+};
+
+//int main()
+//{
+//	UniquePtr<int> up1(new int(10));
+//	cout << "up1:" << up1.get() << "  *ptr:" << *up1 << endl;
+//	UniquePtr<int> up2(std::move(up1));                 // 控制权变更
+//	cout << "up1:" << up1.get() << endl;		        // nullptr, 此时 up1 已无控制权
+//	cout << "up2:" << up2.get() << "  *ptr:" << *up2 << endl;
+//	
+//	UniquePtr<int> up3(new int(30));
+//	UniquePtr<int> up4(new int(40));
+//	cout << "up3:" << up3.get() << "  *ptr:" << *up3 << endl;
+//	cout << "up4:" << up4.get() << "  *ptr:" << *up4 << endl;
+//	up3 = std::move(up2);                               // 控制权变更
+//	cout << "up3:" << up3.get() << "  *ptr:" << *up3 << endl;
+//	cout << "up4:" << up4.get() << "  *ptr:" << *up4 << endl;
+//	up3.swap(up4);
+//	cout << "up3:" << up3.get() << "  *ptr:" << *up3 << endl;
+//	cout << "up4:" << up4.get() << "  *ptr:" << *up4 << endl;
+//	
+//	up3.release();
+//	cout << "up3:" << up3.get() << endl;
+//	
+//	std::cout << "Hello World!\n";
+//	return 0;
+//}
+
+/*******************************************************************
+ * 打印结果:
+ * no default constructor
+ * up1:01355E78  *ptr:10
+ * move constructor
+ * up1:00000000
+ * up2:01355E78  *ptr:10
+ * no default constructor
+ * no default constructor
+ * up3:01355AF0  *ptr:30
+ * up4:01355B20  *ptr:40
+ * move assignment constructor
+ * up3:01355E78  *ptr:10
+ * up4:01355B20  *ptr:40
+ * up3:01355B20  *ptr:40
+ * up4:01355E78  *ptr:10
+ * up3:00000000
+ * Hello World!
+ * destructor
+ * destructor
+ * destructor
+ * destructor
+ ******************************************************************/