vlib/v/checker/tests/overload_return_type.vv:14:11: error: cannot assign to `two`: expected `Point`, not `int`
   12 |     mut one := Point {x:1, y:2}
   13 |     mut two := Point {x:5, y:1}
   14 |     two = one + two
      |           ~~~~~~~~~
   15 | }