#define LED 13
#define prnt   Serial.print
#define prntln Serial.println
#define setPin digitalWrite
#define getPin digitalRead

#define LITERAL(...) "" #__VA_ARGS__

/* ---------------------------------- */

/*
typedef void (*foobar)() fubarfn;
void Fun(fubarfn& baz){
   fubarfn = baz;
   baz();
}
*/

int Default  = 111;
int Variable = 42;

// function with pointer as argument
void FunByRef(int& iPtr){
  iPtr++;
}
void FunByRefDef(int& iPtr=Default){
  prntln(iPtr);
}
/* ---------------------------------- */

void setup() {
  Serial.begin(9600);
  int n,x = 1;        // declare vars

  prnt(LITERAL(n)),prnt(": ");prntln(n);
  FunByRef(n);
  prnt(LITERAL(n)),prnt(": ");prntln(n);prntln();

  prnt(LITERAL(x)),prnt(": ");prntln(x);
  FunByRef(x);
  prnt(LITERAL(x)),prnt(": ");prntln(x);prntln();

  /* - - - - - - - - - - - - - - - - - */

  FunByRefDef();
  FunByRefDef(Variable);
}
/* ---------------------------------- */

void loop() {
  delay(1);
}