static function pointer to non-static function member
-
I look for a piece of advise:
I need to trigger a non-static function member of my MyClass when any of the 256 objects of type MeterClass changes. I am trying by using a static function pointer but I am not able to call a non-static function in object "programa" of type MyClass.
Function I need to call is in fact a non-static member of other class. I tryed pointing to a global function and it worked ok but now, I need to point to a non-static member of other class but it does not compile.class MeterClass{ public: void setValue(unsigned long x){ m = x; cb_update(); // here I call pointed func when value changes } static void (* cb_update)(void); //pointer to func to call when meter changes private: unsigned long m; } class MyClass{ public: MeterClass meter[256]; // create 256 instances of MeterClass void objectHasBeenUpdated(void){ /* action */ } // non-static function to call when a meter changes //... code follow describing behaviour, at any time, one meter changes, let's say meter[10].setValue(5); } int main(int argc, char *argv[]) { QApplication app(argc, argv); MyClass programa; MeterClass::cb_update = programa.objectHasBeenUpdated; // <--this does not work, does not compile return app.exec(); }I am sorry if it is not clear, I dont want to be so extensive. Should I try with other resources? signals and slots?
I hope anybody could advise.
Thank you very much -
I look for a piece of advise:
I need to trigger a non-static function member of my MyClass when any of the 256 objects of type MeterClass changes. I am trying by using a static function pointer but I am not able to call a non-static function in object "programa" of type MyClass.
Function I need to call is in fact a non-static member of other class. I tryed pointing to a global function and it worked ok but now, I need to point to a non-static member of other class but it does not compile.class MeterClass{ public: void setValue(unsigned long x){ m = x; cb_update(); // here I call pointed func when value changes } static void (* cb_update)(void); //pointer to func to call when meter changes private: unsigned long m; } class MyClass{ public: MeterClass meter[256]; // create 256 instances of MeterClass void objectHasBeenUpdated(void){ /* action */ } // non-static function to call when a meter changes //... code follow describing behaviour, at any time, one meter changes, let's say meter[10].setValue(5); } int main(int argc, char *argv[]) { QApplication app(argc, argv); MyClass programa; MeterClass::cb_update = programa.objectHasBeenUpdated; // <--this does not work, does not compile return app.exec(); }I am sorry if it is not clear, I dont want to be so extensive. Should I try with other resources? signals and slots?
I hope anybody could advise.
Thank you very much@ivanperino
Hello,
Static functions and global functions can be called the same way. Non-static functions (members) can be called through the pointer-to-member operators, but you need an object in addition to the member pointer.Look also here.
Kind regards.
