update

basic_content/friend/friend_func.cpp

@@ -0,0 +1,33 @@
+/**
+ * @file friend_func.cpp
+ * @brief 友元函数
+ * @author 光城
+ * @version v1
+ * @date 2019-08-06
+ */
+
+#include <iostream>
+
+using namespace std;
+
+class A
+{
+public:
+    A(int _a):a(_a){};
+    friend int geta(A &ca);  ///< 友元函数
+private:
+    int a;
+};
+
+int geta(A &ca) 
+{
+    return ca.a;
+}
+
+int main()
+{
+    A a(3);    
+    cout<<geta(a)<<endl;
+
+    return 0;
+}