On Thursday, 1 August 2013 at 16:36:34 UTC, Ali Çehreli wrote:
On 08/01/2013 03:29 AM, JS wrote:
> On Thursday, 1 August 2013 at 05:22:46 UTC, Ali Çehreli wrote:
>> On 07/31/2013 06:10 PM, JS wrote:
>>> http://dpaste.dzfl.pl/dbb40dbc
>>>
>>> The code was pared down from a lot of string mixin code
generation. I
>>> nest the structs because I want a nested enums. I don't
want have to
>>> have eState and eStateType but eState and eState.Type.
>>>
>>> Having the ability to nest enums would solve my problem.
>>>
>>> Regardless, I can almost achieve the effect with nested
structs but not
>>> quite.
>>>
>>> In the code, I cannot assign to the struct for some reason
even with
>>> alias this on iB, which should make State act like the int
Value.
>>>
>>> i.e.,
>>>
>>> b.State.Value = Enums.State.A;
>>>
>>> works but
>>>
>>> b.State = Enums.State.A;
>>>
>>> doesn't
>>>
>>> It maybe some stupid error on my part but I can't keep my
eyes open
>>> enough to figure it out...
>>>
>>>
>>>
>>
>> For that assignment to work, the left-hand side must be
assignable.
>> However, the property function State() returns Enums.eState
by-value.
>>
>> The following has the same issue:
>>
>> struct S
>> {
>> int i_;
>>
>> @property int i() {
>> return i_;
>> }
>>
>> alias i this;
>> }
>>
>> void main()
>> {
>> auto s = S();
>> s = 42;
>> assert(s.i == 42);
>> }
>>
>> Error: cannot implicitly convert expression (42) of type int
to S
>>
>> To compile, i() must return an lvalue:
>>
>> @property ref int i() {
Although, what I said seems more like a workaround because you
already had a setter @property. You shouldn't need to make the
getter return a reference as well... I guess...
I think what is at play here is the current implementation
limitation of "a single 'alias this' per type." I think 'alias
this' happens to pick the getter perhaps because the getter
function is defined first in the class. I don't know...
Ali
So, a ref'ed getter is the same as a setter?
Also, it would see, I'm guessing, that using alias this on a
property and having to ref will bypass the setter?
