a must-non constant alias argument with its default argument must be constant

[marhuum]

How do we code a must-non constant alias argument with its default argument must be constant as it's being non referenced ?
as this fail

Bar {
  int on;
  Bar(){};
  Bar(bool o): off{o}{}
  bool off; 
}

int fooBar(int board, Bar& bar = static_cast<Bar>(1)) {

//...
}

gcc show:

error: cannot bind non-const lvalue reference of type 'Bjavascript:editbox1.editSend()ar&' to an rvalue of type 'Bar'

How to solve

[H00G0]

If you're trying to declare a struc you need the prefix struct in front of Bar.
And to define your function fooBar you would also need to add Bar:: int Bar::fooBar(int board, Bar& bar = static_cast<Bar>(1)) {}