book: translate ch02

Update #12

code/2/2.19.delegate.constructor.cpp

@@ -1,11 +1,11 @@
 //
-// 2.7.cpp
+// 2.19.constructor.cpp
+// chapter 2 language usability
 // modern c++ tutorial
 //
 // created by changkun at changkun.de
 // https://github.com/changkun/modern-cpp-tutorial
 //
-// 面向对象增强
 
 #include <iostream>
 #include <string>
@@ -18,12 +18,12 @@ public:
         str = s;
     }
     
-    // 委托构造
+    // delegate constructor
     Base(std::string s, int v) : Base(s) {
         value = v;
     }
     
-    // 终止重载
+    // final constructor
     virtual void foo() final {
         return;
     }
@@ -36,26 +36,26 @@ public:
     double floating;
     Subclass() = delete;
     
-    // 继承构造
+    // inherit constructor
     Subclass(double f, int v, std::string s) : Base(s, v) {
         floating = f;
     }
     
-    // 显式重载
+    // explifict constructor
     virtual void foo(int v) override {
         std::cout << v << std::endl;
         value = v;
     }
-};  // 合法 final
+};  // legal final
 
 // class Subclass2 : Subclass {
-// };  // 非法, Subclass 已 final
+// };  // illegal, Subclass has final
 // class Subclass3 : Base {
-//    void foo(); // 非法, foo 已 final
+//    void foo(); // illegal, foo has final
 // }
 
 int main() {
-    // Subclass oops; // 非法, 默认构造已删除
+    // Subclass oops; // illegal, default constructor has deleted
     Subclass s(1.2, 3, "abc");
     
     s.foo(1);

code/2/2.20.strong.type.enum.cpp

@@ -1,11 +1,10 @@
 //
-// 2.8.cpp
+// 2.20.strong.type.enum.cpp
 // modern c++ tutorial
 //
 // created by changkun at changkun.de
 // https://github.com/changkun/modern-cpp-tutorial
 //
-// 强类型枚举
 
 #include <iostream>
 template<typename T>
@@ -14,7 +13,7 @@ std::ostream& operator<<(typename std::enable_if<std::is_enum<T>::value, std::os
     return stream << static_cast<typename std::underlying_type<T>::type>(e);
 }
 
-// 如果两个都定义为 value1 和 value2，将引发重定义错误
+// there will be compile error if all define value1 和 value2
 enum Left {
     left_value1 = 1,
     left_value2
@@ -37,8 +36,8 @@ int main() {
         std::cout << "Left::value1 == Right::value2" << std::endl;
     }
     
-    // 引发编译错误
-    // if(new_enum::value1 == 1) {
+    // compile error
+    // if(new_enum::left_value1 == 1) {
     //     std::cout << "true!" << std::endl;
     // }
     if (new_enum::value3 == new_enum::value4) {