Question

The compiler is not recognizing my object heatingUnit as a type of the class HeatingUnit. I have no idea why?

// Jimoh Ovbiagele (JAO945)

#include <iostream>
#include <stdio.h>
#include <stdbool.h>
#include "HeatingUnit.h"

class BangBangControl{

public:

  HeatingUnit *heatingUnit;
  int tempToMaintain;


BangBangControl(int temp, bool isOn, int initialTemp)
: heatingUnit(new HeatingUnit(isOn, initialTemp)),
  tempToMaintain(temp){

}

void setTemp(int newTemp){
  tempToMaintain = newTemp;
}

int getTemp(){
  return tempToMaintain;
}

int update(){
  int i = heatingUnit.tick();
  if (i > tempToMaintain + 2) heatingUnit.turnOff();
  if (i < tempToMaintain - 2) heatingUnit.turnOn();
  return i;
}

int main(){
  BangBangControl bBC(50, true, 0);

  for(int i = 0; i < 100; i++){        
    std::cout << "Temp to maintain is: " << bBC.getTemp() << " Current temp is: " << bBC.update() << "\n"; 

  }

  return(0);
}


};

I receive this error log

BangBangControl.cpp: In member function ‘int BangBangControl::update()’:
BangBangControl.cpp:31: error: request for member ‘tick’ in ‘((BangBangControl*)this)->BangBangControl::heatingUnit’, which is of non-class type ‘HeatingUnit*’
BangBangControl.cpp:32: error: request for member ‘turnOff’ in ‘((BangBangControl*)this)->BangBangControl::heatingUnit’, which is of non-class type ‘HeatingUnit*’
BangBangControl.cpp:33: error: request for member ‘turnOn’ in ‘((BangBangControl*)this)->BangBangControl::heatingUnit’, which is of non-class type ‘HeatingUnit*’

Answer 1

You’ve got a pointer to HeatingUnit which you need to dereference when you go to apply methods on it, so your update method should be:

int update(){
    int i = heatingUnit->tick();
    if (i > tempToMaintain + 2) heatingUnit->turnOff();
    if (i < tempToMaintain - 2) heatingUnit->turnOn();
    return i;
}