support bazel complie this project and format code.

basic_content/virtual/set2/BUILD

@@ -0,0 +1,8 @@
+# please run `bazel run basic_content/virtual/set2:default_arg`
+load("@rules_cc//cc:defs.bzl", "cc_binary")
+
+cc_binary(
+    name = "default_arg",
+    srcs = ["default_arg.cpp"],
+    copts = ["-std=c++11"]
+)

basic_content/virtual/set2/default_arg.cpp

@@ -7,33 +7,22 @@
  * @date 2019-07-24
  */
 
-#include <iostream> 
-using namespace std; 
+#include <iostream>
+using namespace std;
 
-class Base 
-{ 
-    public: 
-        virtual void fun ( int x = 10 ) 
-        { 
-            cout << "Base::fun(), x = " << x << endl; 
-        } 
-}; 
+class Base {
+public:
+  virtual void fun(int x = 10) { cout << "Base::fun(), x = " << x << endl; }
+};
 
-class Derived : public Base 
-{ 
-    public: 
-        virtual void fun ( int x=20 ) 
-        { 
-            cout << "Derived::fun(), x = " << x << endl; 
-        } 
-}; 
-
-
-int main() 
-{ 
-    Derived d1; 
-    Base *bp = &d1; 
-    bp->fun();  // 10
-    return 0; 
-} 
+class Derived : public Base {
+public:
+  virtual void fun(int x = 20) { cout << "Derived::fun(), x = " << x << endl; }
+};
 
+int main() {
+  Derived d1;
+  Base *bp = &d1;
+  bp->fun(); // 10
+  return 0;
+}