Differences

This shows you the differences between two versions of the page.

--- c:c_callback_functions [2021/04/28 08:27] – created peter
+++ c:c_callback_functions [2021/04/28 08:34] (current) – peter
@@ Line 1: / Line 1: @@
-====== C - C++ - Callback functions ======
+====== C - C++ Callback functions ======
+===== callback_function.hpp =====
-[[C:C++ Callback functions|C++ Callback functions]]
+<code cpp>
+#pragma once
+#include <string>
+// Define a callback function based on a class method and call it with argument "output".
+void use_callback_function(std::string output);
+</code>
+----
+===== callback_function.cpp =====
+<code cpp>
+#include "callback_function.hpp"
+#include <string>
+#include <iostream>
+#include <functional>
+class MyClass
+{
+public:
+  static void mystaticfunction(std::string str)
+  {
+    std::cout << str << std::endl;
+  }
+  void mymemberfunction(std::string str)
+  {
+    mystaticfunction(str);
+  }
+};
+void test(std::string str, std::function<void(std::string)> callBack = nullptr)
+{
+  if (callBack)
+  {
+    callBack(str);
+  }
+}
+void use_callback_function(std::string output)
+{
+  // Sample 1.
+  test(output, MyClass::mystaticfunction);
+  // Sample 2.
+  MyClass myClass;
+  auto callBack = [&myClass](std::string str)
+  {
+    myClass.mymemberfunction(str);
+  };
+  test(output, callBack);
+}
+</code>
+----
+===== References =====
+https://en.cppreference.com/w/cpp/utility/functional/function