revision #1: 更新第二章中已维护的代码

code/2/2.6.auto.cpp

@@ -0,0 +1,42 @@
+//
+// 2.6.auto.cpp
+// chapter 2 language usability
+// modern cpp tutorial
+//
+// created by changkun at changkun.de
+//
+
+#include <initializer_list>
+#include <vector>
+#include <iostream>
+
+class MagicFoo {
+public:
+    std::vector<int> vec;
+    MagicFoo(std::initializer_list<int> list) {
+        for (auto it = list.begin(); it != list.end(); ++it) {
+            vec.push_back(*it);
+        }
+    }
+};
+
+// wrong
+// int add(auto x, auto y) {
+//     return x+y;
+// }
+
+int main() {
+    MagicFoo magicFoo = {1, 2, 3, 4, 5};
+    std::cout << "magicFoo: ";
+    for (auto it = magicFoo.vec.begin(); it != magicFoo.vec.end(); ++it) {
+        std::cout << *it << ", ";
+    }
+    std::cout << std::endl;
+
+    auto i = 5;                 // type int
+    auto j = 6;                 // type int
+    auto arr = new auto(10);    // type int*
+    // auto auto_arr2[10] = arr;
+    // std::cout << add(i, j) << std::endl;
+    return 0;
+}