class A {
  foo : int;

  public this () {
    def bar (x) {
      foo = x; // E: assignment to immutable field
    }
    if (1 == 1)
      bar (1);
    else
      bar (2);
  }
}

class B {
  foo : int;
  meth : int -> void;

  public this () {
    def bar (x) {
      foo = x;  // E: assignment to immutable field
    }
    if (1 == 1)
      bar (1);
    else
      bar (2);
    meth = bar;
  }
}

class C {
  foo () : void {
    def x = 1 :: [];
    x.tl = [2]; // E: needed a writable location for assignment target, got a reference to field `tl', which is read-only
  }
}

struct Str {
    public this(x : int) { 
        base = x // E: needed a writable location for assignment target
    }
}