indexed access: 10 ways to fix 'harmfull' issue

[Ruslan Shevchenko]

 And if we want allow programmer return result of assignment in own
classes, that this rules must be applied if right part is collection,
which are not implement additional 'getter/setter interfaces'.


Also, statement that (7) will have same problems, as original (3) in my
previous list is incorrect)

(i. e. solution (7) also clear.)


> require in specification of assignment
> 1.  if indexed setter call require autoboxing or integer type conversions
> -
>   do one first and store in temporary variable
> 2.  call setter with stored temporary variable (let call one boxedRight)
> 3.  return boxedRight
>