add 06

02/03a/0.cpp

@@ -0,0 +1,22 @@
+#include <iostream>
+#include <string>
+
+struct Pig {
+    std::string m_name;
+    int m_weight;
+
+    Pig()
+    {
+        m_name = "佩奇";
+        m_weight = 80;
+    }
+};
+
+int main() {
+    Pig pig;
+
+    std::cout << "name: " << pig.m_name << std::endl;
+    std::cout << "weight: " << pig.m_weight << std::endl;
+
+    return 0;
+}

02/03a/1.cpp

@@ -0,0 +1,19 @@
+#include <iostream>
+#include <string>
+
+struct Pig {
+    std::string m_name;
+    int m_weight;
+
+    Pig() : m_name("佩奇"), m_weight(80)
+    {}
+};
+
+int main() {
+    Pig pig;
+
+    std::cout << "name: " << pig.m_name << std::endl;
+    std::cout << "weight: " << pig.m_weight << std::endl;
+
+    return 0;
+}

02/03a/2.cpp

@@ -0,0 +1,19 @@
+#include <iostream>
+#include <string>
+
+struct Pig {
+    std::string m_name;
+    int m_weight;
+
+    Pig(std::string name, int weight) : m_name(name), m_weight(weight)
+    {}
+};
+
+int main() {
+    Pig pig("佩奇", 80);
+
+    std::cout << "name: " << pig.m_name << std::endl;
+    std::cout << "weight: " << pig.m_weight << std::endl;
+
+    return 0;
+}

02/03a/3.cpp

@@ -0,0 +1,21 @@
+#include <iostream>
+#include <string>
+
+struct Pig {
+    std::string m_name;
+    int m_weight;
+
+    Pig(int weight)
+        : m_name("一只重达" + std::to_string(weight) + "kg的猪")
+        , m_weight(weight)
+    {}
+};
+
+int main() {
+    Pig pig(80);
+
+    std::cout << "name: " << pig.m_name << std::endl;
+    std::cout << "weight: " << pig.m_weight << std::endl;
+
+    return 0;
+}

02/03a/4.cpp

@@ -0,0 +1,21 @@
+#include <iostream>
+#include <string>
+
+struct Pig {
+    std::string m_name;
+    int m_weight;
+
+    Pig(int weight)
+        : m_name("一只重达" + std::to_string(weight) + "kg的猪")
+        , m_weight(weight)
+    {}
+};
+
+int main() {
+    Pig pig = 80;
+
+    std::cout << "name: " << pig.m_name << std::endl;
+    std::cout << "weight: " << pig.m_weight << std::endl;
+
+    return 0;
+}

02/03a/5.cpp

@@ -0,0 +1,22 @@
+#include <iostream>
+#include <string>
+
+struct Pig {
+    std::string m_name;
+    int m_weight;
+
+    explicit Pig(int weight)
+        : m_name("一只重达" + std::to_string(weight) + "kg的猪")
+        , m_weight(weight)
+    {}
+};
+
+int main() {
+    // Pig pig = 80;  // 编译错误
+    Pig pig(80);      // 编译通过
+
+    std::cout << "name: " << pig.m_name << std::endl;
+    std::cout << "weight: " << pig.m_weight << std::endl;
+
+    return 0;
+}

02/03a/6.cpp

@@ -0,0 +1,24 @@
+#include <iostream>
+#include <string>
+
+struct Pig {
+    std::string m_name;
+    int m_weight;
+
+    explicit Pig(int weight)
+        : m_name("一只重达" + std::to_string(weight) + "kg的猪")
+        , m_weight(weight)
+    {}
+};
+
+void show(Pig pig) {
+    std::cout << "name: " << pig.m_name << std::endl;
+    std::cout << "weight: " << pig.m_weight << std::endl;
+}
+
+int main() {
+    // show(80);    // 编译错误
+    show(Pig(80));  // 编译通过
+
+    return 0;
+}

02/03a/CMakeLists.txt

@@ -0,0 +1,5 @@
+cmake_minimum_required(VERSION 3.12)
+set(CMAKE_CXX_STANDARD 17)
+project(hellocpp LANGUAGES CXX)
+
+add_executable(cpptest 6.cpp)

02/03a/run.sh

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