Properties don't behave like variables?

[Iain Buclaw]

On 7 May 2012 23:23, Artur Skawina <art.08.09 at gmail.com> wrote:
>> On 2012-05-07 21:53, Steven Schveighoffer wrote:
>>
>>> How do you overload the operator for a property? For example:
>
> It can of course be done [1], but i think the question was whether the
> compiler should do the obvious rewrite from 'prop() |= 2' to 'prop(prop()|2)'.
> Unconditionally, as not doing it every time would be confusing and lead
> to bugs where the setter gets bypassed.
> But what about the case where you want to return a ref to /different/
> objects? I guess mandating a setter wouldn't be problem, and still better
> than the alternative.
>
> artur
>
> [1] I shouldn't even be posting this, as someone might actually think about
> using something like it...
>
>   struct S {
>      int i;
>      @property ref p() { return *cast(PropProxy!(typeof(this),"i")*)&this; }
>   }
>
>   int main()
>   {
>      S s;
>      s.p |= 2;
>      return s.p;
>   }
>
>   struct PropProxy(RT, string sym) {
>      @property ref data() { return *cast(RT*)&this; }
>      @property ref get() { return __traits(getMember, data, sym); }
>      alias get this;
>      auto opOpAssign(string op, T)(T b) {
>         return mixin("data." ~ sym ~ " " ~ op ~ "= b");
>      }
>   }
>
> Keep in mind this isn't a serious suggestion, more of a joke; i wrote it just
> out of curiosity, to check if GDC would be able to turn it all into
> "mov $0x2, %eax; ret;". ;)
>

Your wishful thinking serves you well. :-)


-- 
Iain Buclaw

*(p < e ? p++ : p) = (c & 0x0f) + '0';