添加C++ native工程代码

cppLib/library.cpp

@@ -0,0 +1,21 @@
+#include "library.h"
+
+#include <iostream>
+
+Calculate& Calculate::getInstance() {
+    // 使用静态局部变量确保线程安全地初始化单例对象
+    static Calculate instance;
+    return instance;
+}
+
+int Calculate::add(int a, int b) {
+    return a + b;
+}
+
+CalculateInfo Calculate::getInfo() {
+    CalculateInfo info;
+    info.name = "Calculate";
+    info.versionName = "Calculate_v1.0.0";
+    info.versionCode = 1;
+    return info;
+}