warning: invalid conversion from 'long int (*)()' to 'long int' in simple call

I have a VB.net background and I am experimenting with an Arduino Mega 2560 as digital pins to try testing an external relay board. I am having trouble with my C code. There must be something stupid im doing.

I am calling the function ReadAllDigitalInputPins() to get back a long as a bit mask, one bit representing the digital input state of each pin.

The compiler is whinging as follows:

warning: invalid conversion from ‘long int (*)()’ to ‘long int’ [-fpermissive]
long result = ReadAllDigitalInputPins;
^~~~~~~~~~~~~~~~~~~~~~~

I read some other references to this error but they dont seem to be relevant. I am not using pointers etc. Any thoughts as to what I am doing wrong? Thanks for any advice.

void ActivateEnableRelayAndCheckPins()  {
  digitalWrite(EnableRelay, HIGH);  //Write a hi to the pin, which switches the ULN2003 low to energize the relay
  delay(settlingTime); //Wait X ms for pins to settle after relays close etc.
  long result =  ReadAllDigitalInputPins;
}


long ReadAllDigitalInputPins() {
  long allPortBits = 0;
  byte inputPins[] = {CH1TermNO, CH1TermNC, CH2TermNO, CH2TermNC};
  for (byte i = 0; i <= sizeof(inputPins) - 1; i++) { 
    int value = digitalRead(inputPins[i]);
    allPortBits = allPortBits << 1;  //shift existing bits over one
    if (value == HIGH) {
      bitWrite(allPortBits, 0, 1);
    }else  {
      bitWrite(allPortBits, 0, 0);
    }
  }
  return allPortBits;
}

Fix:

 long result =  ReadAllDigitalInputPins();

"ReadAllDigitalInputPins" by itself is a variable of type "long int (*)()" which is a function pointer.

Wow thanks so much for the fast response. You are the best. Much appreciated!!