add zonejie

02/10/main.cpp

@@ -2,41 +2,41 @@
 #include <vector>
 
 void test_copy() {
-    std::cout << std::endl << "test copy:" << std::endl;
-
     std::vector<int> v1(10);
     std::vector<int> v2(200);
 
-    std::cout << "before:" << std::endl;
-    std::cout << "v1.size() is " << v1.size() << std::endl;
-    std::cout << "v2.size() is " << v2.size() << std::endl;
-
-    v2 = v1;
+    v1 = v2;                  // 拷贝赋值 O(n)
 
-    std::cout << "after:" << std::endl;
-    std::cout << "v1.size() is " << v1.size() << std::endl;
-    std::cout << "v2.size() is " << v2.size() << std::endl;
+    std::cout << "after copy:" << std::endl;
+    std::cout << "v1 length " << v1.size() << std::endl;  // 200
+    std::cout << "v2 length " << v2.size() << std::endl;  // 200
 }
 
 void test_move() {
-    std::cout << std::endl << "test move:" << std::endl;
-
     std::vector<int> v1(10);
     std::vector<int> v2(200);
 
-    std::cout << "before:" << std::endl;
-    std::cout << "v1.size() is " << v1.size() << std::endl;
-    std::cout << "v2.size() is " << v2.size() << std::endl;
+    v1 = std::move(v2);      // 移动赋值 O(1)
+
+    std::cout << "after move:" << std::endl;
+    std::cout << "v1 length " << v1.size() << std::endl;  // 200
+    std::cout << "v2 length " << v2.size() << std::endl;  // 0
+}
+
+void test_swap() {
+    std::vector<int> v1(10);
+    std::vector<int> v2(200);
 
-    v2 = std::move(v1);
+    std::swap(v1, v2);      // 交换两者 O(1)
 
-    std::cout << "after:" << std::endl;
-    std::cout << "v1.size() is " << v1.size() << std::endl;
-    std::cout << "v2.size() is " << v2.size() << std::endl;
+    std::cout << "after swap:" << std::endl;
+    std::cout << "v1 length " << v1.size() << std::endl;  // 200
+    std::cout << "v2 length " << v2.size() << std::endl;  // 10
 }
 
 int main() {
     test_copy();
     test_move();
+    test_swap();
     return 0;
 }

02/11/CMakeLists.txt

@@ -0,0 +1,5 @@
+cmake_minimum_required(VERSION 3.12)
+set(CMAKE_CXX_STANDARD 17)
+project(hellocpp LANGUAGES CXX)
+
+add_executable(cpptest main.cpp)

02/11/main.cpp

@@ -0,0 +1,65 @@
+#include <cstdlib>
+#include <iostream>
+#include <cstring>
+
+struct Vector {
+    size_t m_size;
+    int *m_data;
+
+    Vector(size_t n) {
+        m_size = n;
+        m_data = (int *)malloc(n * sizeof(int));
+    }
+
+    ~Vector() {
+        free(m_data);
+    }
+
+    Vector(Vector const &other) {
+        m_size = other.m_size;
+        m_data = (int *)malloc(m_size * sizeof(int));
+        memcpy(m_data, other.m_data, m_size * sizeof(int));
+    }
+
+    Vector &operator=(Vector const &other) {
+        m_size = other.m_size;
+        m_data = (int *)realloc(m_data, m_size * sizeof(int));
+        memcpy(m_data, other.m_data, m_size * sizeof(int));
+        return *this;
+    }
+
+    Vector(Vector &&other) {
+        m_size = other.m_size;
+        other.m_size = 0;
+        m_data = other.m_data;
+        other.m_data = nullptr;
+    }
+
+    Vector &operator=(Vector &&other) {
+        this->~Vector();
+        new (this) Vector(std::move(other));
+        return *this;
+    }
+
+    size_t size() {
+        return m_size;
+    }
+
+    void resize(size_t size) {
+        m_size = size;
+        m_data = (int *)realloc(m_data, m_size);
+    }
+
+    int &operator[](size_t index) {
+        return m_data[index];
+    }
+};
+
+int main() {
+    Vector v1(32);
+    Vector v2(64);
+
+    v2 = std::move(v1);
+
+    return 0;
+}

02/11/run.sh

@@ -0,0 +1,5 @@
+set -e
+
+cmake -B build
+cmake --build build
+build/cpptest

02/11/zongjie.cpp

@@ -0,0 +1,9 @@
+C c1 = c2;               // 拷贝构造函数
+C c1 = std::move(c2);    // 移动构造函数
+
+c1 = c2;                 // 拷贝赋值函数
+c1 = std::move(c2);      // 移动赋值函数
+
+C c1 = C();              // 移动构造函数
+c1 = C();                // 移动赋值函数
+return c2;               // 移动赋值函数