revision #1: 更新第二章中已维护的代码

code/2/2.4.initializer.list.cpp

@@ -0,0 +1,59 @@
+//
+// 2.4.initializer.list.cpp
+// chapter 2 language usability
+// modern cpp tutorial
+//
+// created by changkun at changkun.de
+//
+
+#include <iostream>
+#include <initializer_list>
+#include <vector>
+
+class Foo {
+public:
+    int value_a;
+    int value_b;
+    Foo(int a, int b) : value_a(a), value_b(b) {}
+};
+
+class MagicFoo {
+public:
+    std::vector<int> vec;
+    MagicFoo(std::initializer_list<int> list) {
+        for (std::initializer_list<int>::iterator it = list.begin(); it != list.end(); ++it) {
+            vec.push_back(*it);
+        }
+    }
+    void foo(std::initializer_list<int> list) {
+        for (std::initializer_list<int>::iterator it = list.begin(); it != list.end(); ++it) {
+            vec.push_back(*it);
+        }
+    }
+};
+
+int main() {
+    // before C++11
+    int arr[3] = {1, 2, 3};
+    Foo foo(1, 2);
+    std::vector<int> vec = {1, 2, 3, 4, 5};
+
+    // after C++11
+    MagicFoo magicFoo = {1, 2, 3, 4, 5};
+    magicFoo.foo({6,7,8,9});
+    Foo foo2 {3, 4};
+
+    std::cout << "arr[0]: " << arr[0] << std::endl;
+    std::cout << "foo:" << foo.value_a << ", " << foo.value_b << std::endl;
+    std::cout << "vec: ";
+    for (std::vector<int>::iterator it = vec.begin(); it != vec.end(); ++it) {
+        std::cout << *it << std::endl;
+    }
+    std::cout << "magicFoo: ";
+    for (std::vector<int>::iterator it = magicFoo.vec.begin(); it != magicFoo.vec.end(); ++it) {
+        std::cout << *it << std::endl;
+    }
+    std::cout << "foo2: " << foo2.value_a << ", " << foo2.value_b << std::endl;
+
+    return 0;
+}