This doesn't make sense regarding alias this a static function
Steven Schveighoffer
schveiguy at gmail.com
Sun May 16 17:11:23 UTC 2021
On 5/16/21 12:48 PM, 12345swordy wrote:
> On Sunday, 16 May 2021 at 16:38:08 UTC, Steven Schveighoffer wrote:
>> On Sunday, 16 May 2021 at 15:45:48 UTC, 12345swordy wrote:
>>> ```struct TIntStatic
>>> {
>>> static int mX;
>>>
>>> static @property int x() { return mX; }
>>> static @property void x(int v) { mX = v; }
>>>
>>> alias x this;
>>> }
>>> ```
>>>
>>> It doesn't like the following code
>>> ```
>>>
>>> alias t = TIntStatic;
>>> t(5);
>>> ```
>>> Yet is perfectly fine with this
>>> ```
>>> alias t = TIntStatic;
>>> t = 5;
>>> ```
>>> What is with the inconsistency? If you allow t = 5 then surely you
>>> must allow t(5) as part of alias this a function.
>>
>> That’s considered a constructor. And there’s no member to accept the 5.
>>
>
> You mean that this shouldn't work?
> ```
> alias t = TIntStatic;
> t = 5;
> ```
Honestly, I'm not sure. `alias this` usually maps to a `this`, i.e. an
instance, not the type. I'm sure it's some quirk in how the compiler
treats alias this, but I wouldn't have expected it to work.
But the reason the constructor form doesn't work is straightforward --
the constructor t() exists. Therefore, it matches first, not using the
alias this, and it's just a matter of parameter count mismatch that
fails (this is well-trodden ground).
BTW, is there a reason you are using `alias t` instead of the real type? If:
```d
TIntStatic = 5;
```
doesn't work, but yours does, then that seems like a bug to me.
-Steve
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