Ouch: return values as lvalue

[Lionello Lunesu]

"Andrei Alexandrescu (See Website For Email)" 
<SeeWebsiteForEmail at erdani.org> wrote in message 
news:45BF7C8B.3080506 at erdani.org...
> Lionello Lunesu wrote:
>> Consider this home-made const:
>>
>> struct Task {
>>   char[] ID;
>> }
>> private Task _CurrentTask; //mutable
>> public Task CurrentTask() { return _CurrentTask; } //const
>>
>> public void StopTask() {
>>   CurrentTask.ID = null;
>> }
>>
>> Notice the bug? That last line should read "_CurrentTask.ID = null;"
>>
>> Isn't there something the compiler can do to help me catch these bugs?
>
> const will take care of it. The code above fetches a member of an rvalue, 
> which is an lvalue.

Yeah, I know, but it's odd: it's setting a member in a struct that's about 
to be deleted. It's like writing "{ int id=4; }". Wouldn't it be possible 
for the compiler to warn about "code without side-effect" or something?

L.