I am trying to pass a class internal function as a callback function within the class. The error behavior is similar to [this problem][1]. Whatsoever, I was unable to construct working code based on that question's answer. I try to pass over a callback function from within the class,in order to create a finite state machine, inspired by the examples I found on adafruit regarding multithreading. The idea is, that each state can call his successor. The class itself then represents the state machine and I just will call its update function. While the following code does not resemble this utility, it resembles the problem in a minimal example (based on [this larger codepiece][2]): class MyClass { const byte theAnswer = 42; void (*myCallback)(); void setCallback(void (*callback)()) { myCallback = callback; } public: void print_info() { Serial.println(theAnswer); } void call() { myCallback(); } MyClass() { setCallback(&MyClass::print_info); } }; MyClass AClassOfItsOwn(); void setup() { Serial.begin(9600); while (! Serial); // Wait until Serial is ready } void loop() { AClassOfItsOwn.call(); return; } I get the following error code returned: > ...testscript.ino: In constructor 'MyClass::MyClass()': > > testscript:25: error: no matching function for call to > 'MyClass::setCallback(void (MyClass::*)())' > > setCallback(&MyClass::print_info); > > ^ > > ...\testscript.ino:25:41: > note: candidate is: > > ...\testscript.ino:6:12: > note: void MyClass::setCallback(void (*)()) > > void setCallback(void (*callback)()) > > ^ > > ...\testscript.ino:6:12: > note: no known conversion for argument 1 from 'void (MyClass::*)()' > to 'void (*)()' > > ...\testscript.ino: > In function 'void loop()': > > testscript:40: error: request for member 'call' in 'AClassOfItsOwn', > which is of non-class type 'MyClass()' > > AClassOfItsOwn.call(); > > ^ > > exit status 1 no matching function for call to > 'MyClass::setCallback(void (MyClass::*)())' ---------- **fun times with polymorphism** this is what I tried till now. I also tried creating an instance of this wrapper within the actual class to hold the callback, but that did not work either. Sorry I am a bit cumbersome with C++, coming from another language and apparently bit off a bit more than I could chew... class CallbackWrapper { void (*myCallback)(); public: void call() { myCallback(); } void setCallback(void (*callback)()) { myCallback = callback; } }; class MyClass : public CallbackWrapper { const byte theAnswer = 42; public: void print_info() { Serial.println(theAnswer); } MyClass() { CallbackWrapper::setCallback(&MyClass::print_info); } }; trying to store the callback function in a wrapping class (also not working, `'((MyClass*)this)->MyClass::CBW' does not have class type`) class CallbackWrapper { void (*myCallback)(); public: void call() { myCallback(); } void setCallback(void (*callback)()) { myCallback = callback; } }; class MyClass { const byte theAnswer = 42; CallbackWrapper CBW(); public: void print_info() { Serial.println(theAnswer); } void call() { CBW.call(); } MyClass() { CBW.setCallback(&MyClass::print_info); } }; An update on why I want to change the callback function during runtime. Here I try to randomly change the callback function: class MyClass { CallbackWrapper CBW(); public: void do_this() { Serial.println("doing this"); } void do_that() { Serial.println("doing that"); } void call() { CBW.call(); if (rand() > 0.5) { CBW.setCallback(&MyClass::do_this) } else { CBW.setCallback(&MyClass::do_that) } } MyClass() { } }; [1]: http://arduino.stackexchange.com/questions/14480/pass-a-member-function-pointer-to-a-method-of-a-foreign-class-edb-lib [2]: https://learn.adafruit.com/multi-tasking-the-arduino-part-3/put-it-all-together-dot-dot-dot