add EXP

.vscode/settings.json

@@ -40,7 +40,22 @@
         "stdexcept": "cpp",
         "streambuf": "cpp",
         "ctime": "cpp",
-        "cstring": "cpp"
+        "cstring": "cpp",
+        "bit": "cpp",
+        "compare": "cpp",
+        "concepts": "cpp",
+        "ios": "cpp",
+        "iterator": "cpp",
+        "xfacet": "cpp",
+        "xiosbase": "cpp",
+        "xlocale": "cpp",
+        "xlocinfo": "cpp",
+        "xlocnum": "cpp",
+        "xmemory": "cpp",
+        "xstddef": "cpp",
+        "xstring": "cpp",
+        "xtr1common": "cpp",
+        "xutility": "cpp"
     },
     "cmake.configureOnOpen": false
 }

EXP/CMakeLists.txt

@@ -0,0 +1,17 @@
+cmake_minimum_required(VERSION 3.10)
+set(CMAKE_CXX_COMPILER "g++")#设置C++编译器
+set(CMAKE_CXX_FLAGS "-g -Wall")
+
+set(CMAKE_CXX_STANDARD 17)        # 使用C++17标准
+
+PROJECT (proj CXX)
+ADD_EXECUTABLE(main main.cpp)
+ADD_EXECUTABLE(main2 main2.cpp)
+ADD_EXECUTABLE(main3 main3.cpp)
+ADD_EXECUTABLE(main4 main4.cpp)
+ADD_EXECUTABLE(main5 main5.cpp)
+ADD_EXECUTABLE(main6 main6.cpp)
+ADD_EXECUTABLE(main8 main8.cpp)
+ADD_EXECUTABLE(main9 main9.cpp)
+ADD_EXECUTABLE(main10 main10.cpp)
+ADD_EXECUTABLE(main11 main11.cpp)

EXP/main.cpp

@@ -0,0 +1,15 @@
+#include<iostream>  
+
+int main(){
+    int a[2][3] = {{1,2,3},{4,5,6}};
+    int (*p)[3] = a; 
+    std::cout << *(*(a+1)+2) << std::endl;
+    std::cout << *(*(p+1)+2) << std::endl;
+    std::cout << p[1][2] << std::endl; 
+    std::cout << typeid(a).name() << std::endl; 
+    std::cout << typeid(&a).name() << std::endl; 
+    std::cout << typeid(&p).name() << std::endl; 
+
+    int *pp =  a[0];
+    std::cout <<typeid(a[0]).name();  
+}

EXP/main10.cpp

@@ -0,0 +1,23 @@
+#include<iostream> 
+
+class Base{
+public:
+    int a = 1; 
+    void show(int a = 111){ this-> a = a ; std::cout <<"show function of Class Base, a = " << a << std::endl;}
+};
+
+class Son : public Base{
+public:
+    int a = 4;
+    void show(int a = 444 ){ this-> a = a; std::cout <<"show function of Class Son, a = " << a << std::endl; this->Base::show();}
+};
+/* 输出
+show function of Class Son, a = 444
+show function of Class Base, a = 111
+*/
+int main(){
+    Son* sn = new Son();
+    sn->show();
+    return 0;  
+}
+

EXP/main11.cpp

@@ -0,0 +1,25 @@
+#include<iostream> 
+
+class Base{
+public:
+    int a = 1; 
+    void show(){ std::cout << "non-param show, a = " << this->a << std::endl; }
+};
+
+class Son : public Base{
+public:
+    int a = 4;
+};
+/* 输出
+non-param show, a = 1
+non-param show, a = 1
+*/
+int main(){
+    Son* sn = new Son();
+    sn->show();
+    sn->Base::show(); 
+
+    delete sn;
+    return 0;  
+}
+

EXP/main2.cpp

@@ -0,0 +1,33 @@
+#include <iostream>
+#include <memory>
+using namespace std;
+class XData
+{
+public:
+    XData()
+    {
+        cout << "Create XData" << endl;
+    }
+    ~XData()
+    {
+        cout << "Drop XData" << endl;
+    }
+};
+int main(int argc,char *argv[])
+{
+    auto sp3 = make_shared<XData>();
+    cout << "sp3.use_count() = " << sp3.use_count() << endl;
+    cout << "before sp3.reset()" << endl; 
+    sp3.reset();
+    cout << "after sp3.reset()" << endl; 
+    cout << "sp3.reset() sp3.use_count() = " << sp3.use_count() << endl;
+    sp3 = nullptr;
+    cout << "after sp3 = nullptr" << endl; 
+    cout << "sp3.reset() sp3.use_count() = " << sp3.use_count() << endl;
+
+    auto sp4 = make_shared<XData>();
+    sp3 = sp4; 
+    cout << "after sp3 = sp4, sp3.use_count() = " << sp3.use_count() << endl; 
+
+    return 0;
+}

EXP/main3.cpp

@@ -0,0 +1,12 @@
+#include<iostream> 
+
+template<class _Ty, size_t Size>
+void TestMemArr(_Ty(&data)[Size])
+{
+    std::cout << "sizeof data : " << std::endl; 
+}
+
+int main(){
+
+    return 0; 
+}

EXP/main4.cpp

@@ -0,0 +1,16 @@
+#include<iostream>
+#include<string>
+
+int main(){
+    std::string str1; 
+    str1.resize(1024);
+    std::cout << str1 << std::endl;
+    for(char a : str1){
+        std::cout << static_cast<int>(a)<< " "; 
+    }
+    std::cout << std::endl; 
+
+    int a; 
+    std::cout << a << std::endl;  
+
+}

EXP/main5.cpp

@@ -0,0 +1,26 @@
+#include <iostream>
+
+// 模板函数，接受一个数组并遍历其元素
+template<size_t Size> 
+void fun(int (&arr)[Size]) {
+    for (auto i : arr) {
+        std::cout << i << " "; // 输出数组中的元素
+    }
+    std::cout << std::endl; // 换行
+}
+
+// 模版函数，更加通用
+template<typename Ty, size_t Size> 
+void fun2(Ty (&arr)[Size]) {
+    for (auto i : arr) {
+        std::cout << i << " "; // 输出数组中的元素
+    }
+    std::cout << std::endl; // 换行
+}
+
+int main() {
+    int a[4] = {1, 2}; // 数组 a，部分初始化，未初始化的元素将被默认初始化为 0
+    fun<4>(a); // 调用模板函数 fun，并传递数组 a (注意： 之所以显示调用模版，是为何防止编译器将其视为模版变量)
+    fun2(a); 
+    return 0;
+}

EXP/main6.cpp

@@ -0,0 +1,42 @@
+#include <iostream>
+#include <cstdlib>
+#include <cstring>
+
+// 全局变量来跟踪分配的总内�?
+size_t allocated_memory = 0;
+
+void* operator new[](std::size_t size) {
+    // 分配内存并记录大�?
+    allocated_memory = size;
+    void* ptr = std::malloc(size);
+    std::cout << "operator new[]: 分配 " << size << " 字节内存，地址: " << ptr << std::endl;
+    return ptr;
+}
+
+void operator delete[](void* ptr) noexcept {
+    // 输出即将释放的内存信�?
+    std::cout << "operator delete[]: 释放地址: " << ptr << std::endl;
+
+    // 模拟修改内存的内�?
+    if (ptr != nullptr) {
+        std::memset(ptr, 0xAA, allocated_memory);  // �?0xAA填充内存
+    }
+
+    // 释放内存
+    std::free(ptr);
+}
+
+int main() {
+    // 分配一个int数组
+    int* arr = new int[1024];
+    std::cout << "数组地址: " << arr << std::endl;
+
+    // 删除数组
+    delete[] arr;
+
+    // 尝试访问数组的元祖 
+    std::cout << "尝试访问已释放的内存: " << arr[0] << std::endl;  // 访问释放后的内存（未定义行为)
+    std::cout << "你好"<<std::endl;
+
+    return 0;
+}

EXP/main7.cpp

@@ -0,0 +1,29 @@
+#include <iostream>
+#include <algorithm> // For std::begin and std::end
+// #include <cstring>   // For memcpy
+
+class XData {
+    int a; 
+    float b; 
+    double c;
+    // Your class definition
+};
+
+int main(int argc, char* argv[]) {
+    XData datas[3];
+    // unsigned char buf[1024] = { 0 };
+
+    // std::cout << "==================memcpy==================" << std::endl;
+    // memcpy(buf, &datas, sizeof(datas));
+
+    // Printing the addresses
+    std::cout << "Address of datas: " << static_cast<void*>(&datas) << std::endl;
+    std::cout << "Address from std::begin(datas): " << static_cast<void*>(std::begin(datas)) << std::endl;
+
+    std::cout << typeid(datas).name() << std::endl; 
+    std::cout << typeid(datas).name() << std::endl; 
+    // std::copy(std::begin(datas), std::end(datas), buf);
+
+    // std::cout << "cppds.com" << std::endl;
+    return 0;
+}

EXP/main8.cpp

@@ -0,0 +1,25 @@
+#include<iostream>  
+
+class TestMem{
+public:
+    TestMem(){
+        std::cout << "this is TestMem constructor" << std::endl;
+    }
+    TestMem(int a ){
+        std::cout << "construct the TestMem by "<< a << std::endl;
+    }
+    TestMem(int a, int b ){
+        std::cout << "construct the TestMem by "<< a << ", " << b << std::endl;
+    }
+    ~TestMem(){
+        std::cout << "thi is TestMem destroy" << std::endl;
+    }
+};
+
+int main(){
+    TestMem* tm = new TestMem[3]{{2,3},2,3};
+    TestMem ta[2] = {};
+    TestMem tb[2]{};           
+
+    return 0; 
+}

EXP/main9.cpp

@@ -0,0 +1,31 @@
+#include<iostream> 
+
+class Base{
+public:
+    int a = 1; 
+    int b = 2; 
+    Base(int a, int b): a(a), b(b){}
+    Base(){
+        std::cout << "this is no params of Base()" <<std::endl; 
+    }
+
+};
+
+class Son : public Base{
+public:
+    int a = 44;
+    int k = 12; 
+    Son(int a, int k): a(a), k(k){
+        std::cout << "bagin Son(int a, int k)" << std::endl; 
+    }
+};
+
+int main(){
+    Base* ba = new Base(111,222);
+    std::cout << ba->a << "  " << ba->b << std::endl; 
+    Son* sn = new Son(333,444);
+    std::cout << sn->a << "  " << sn->k << "  " << sn->b << std::endl;  
+    Base* ba1 = new Base();
+    std::cout << ba1->a << "  " << ba1->b << std::endl; 
+    return 0;  
+}

Link/Link4/CMakeLists.txt

@@ -4,3 +4,4 @@ project(CheckLinkage)
 set(CMAKE_CXX_STANDARD 17)
 
 add_executable(main main.cpp)
+add_executable(main6 main6.cpp)

Link/Link4/main.cpp

@@ -51,7 +51,7 @@ template class TypeClass<int>;  // 实例化声明，会实例化模板
 TypeClass<int> tc;  
 
 template<typename T>
-static T TypeClass<T>::staticKK;  // 泛型定义
+T TypeClass<T>::staticKK;  // 泛型定义
 
 template<> int TypeClass<int>::staticKK = 10;
 

Link/Link4/main6.cpp

@@ -0,0 +1,31 @@
+// Tool::fun()::a 和fun2::a 不冲突，都是局部变量 
+#include <iostream>
+
+class Tool{
+    public:
+        void fun(){
+            static int a = 12; 
+            a += 1; 
+            std::cout << a << std::endl;  
+        }
+        static void fun3(){
+            static int a = 22; 
+            a += 1; 
+        }
+};
+
+void fun2(){
+    static int a = 24;  
+    a+=1;
+}
+
+int main(){
+    Tool tool, tool2; 
+    tool.fun();
+    tool.fun();
+    tool.fun();
+    tool2.fun();
+    tool2.fun();
+    tool.fun3();
+    return 0; 
+}

STL/functor/CMakeLists.txt

@@ -0,0 +1,8 @@
+cmake_minimum_required(VERSION 3.10)
+set(CMAKE_CXX_COMPILER "g++")#设置C++编译器
+set(CMAKE_CXX_FLAGS "-g -Wall")
+
+set(CMAKE_CXX_STANDARD 17)        # 使用C++17标准
+
+PROJECT (proj CXX)
+ADD_EXECUTABLE(main main.cpp)