E4065

Overloaded operator should accept the correct number of arguments.

You can refer to the Operator Overloading section for a list of operators that can be overloaded, and here is a list of number of arguments that each operator should accept:

Operator	Method Name	Number of Arguments
_[_]	op_get	2
_[_] = _	op_set	3
_[_:_]	op_as_view	3

Erroneous example

///|
struct A(Array[Int])

///|
fn A::op_get(self : A, idx : Int, offset? : Int) -> Int {
  //  ^~~~~~
  // Error: overloaded operator "op_get" should accept 2 arguments, but it accepts 3 arguments
  let idx = match offset {
    None => idx
    Some(offset) => idx + offset
  }
  return self.0[idx]
}

Suggestion

Modify the method to match the expected number of arguments of the operator.

///|
struct A(Array[Int])

///|
fn A::op_get(self : A, idx : Int) -> Int {
  return self.0[idx]
}