Hello.

When I do:

---------------------
class MyClass{..}
class YourClass{..}
class OurClass{..}

YourClass yc = new YourClass();

foreach (auto id; [ typeid(MyClass), typeid(YourClass), typeid(OurClass) ])
{
  if (typeid(yc) == id)
  {
    writeln("It works !");
  }
}
---------------------
The compiler says: basic type expected, not auto
Why can't I have one time the type id of MyClass, then of YourClass and of OurClass ?
Is there an alternative ?

On Saturday, 9 April 2016 at 10:10:19 UTC, Lucien wrote:
> Hello.
>
> When I do:
>
> ---------------------
> class MyClass{..}
> class YourClass{..}
> class OurClass{..}
>
> YourClass yc = new YourClass();
>
> foreach (auto id; [ typeid(MyClass), typeid(YourClass), typeid(OurClass) ])
> {
>   if (typeid(yc) == id)
>   {
>     writeln("It works !");
>   }
> }
> ---------------------
> The compiler says: basic type expected, not auto
> Why can't I have one time the type id of MyClass, then of YourClass and of OurClass ?
> Is there an alternative ?

remove auto and optionally replaces it with TypeInfo_Class.

On Saturday, 9 April 2016 at 10:28:05 UTC, Basile B. wrote:
> On Saturday, 9 April 2016 at 10:10:19 UTC, Lucien wrote:
>> Hello.
>>
>> When I do:
>>
>> ---------------------
>> class MyClass{..}
>> class YourClass{..}
>> class OurClass{..}
>>
>> YourClass yc = new YourClass();
>>
>> foreach (auto id; [ typeid(MyClass), typeid(YourClass), typeid(OurClass) ])
>> {
>>   if (typeid(yc) == id)
>>   {
>>     writeln("It works !");
>>   }
>> }
>> ---------------------
>> The compiler says: basic type expected, not auto
>> Why can't I have one time the type id of MyClass, then of YourClass and of OurClass ?
>> Is there an alternative ?
>
> remove auto and optionally replaces it with TypeInfo_Class.

So simple ?! o.o

Thanks !

On Saturday, 9 April 2016 at 10:56:34 UTC, Lucien wrote:
> On Saturday, 9 April 2016 at 10:28:05 UTC, Basile B. wrote:
>> On Saturday, 9 April 2016 at 10:10:19 UTC, Lucien wrote:
>>> Hello.
>>>
>>> When I do:
>>>
>>> ---------------------
>>> class MyClass{..}
>>> class YourClass{..}
>>> class OurClass{..}
>>>
>>> YourClass yc = new YourClass();
>>>
>>> foreach (auto id; [ typeid(MyClass), typeid(YourClass), typeid(OurClass) ])
>>> {
>>>   if (typeid(yc) == id)
>>>   {
>>>     writeln("It works !");
>>>   }
>>> }
>>> ---------------------
>>> The compiler says: basic type expected, not auto
>>> Why can't I have one time the type id of MyClass, then of YourClass and of OurClass ?
>>> Is there an alternative ?
>>
>> remove auto and optionally replaces it with TypeInfo_Class.
>
> So simple ?! o.o
>
> Thanks !

FYI the things that you can put there (in place of auto) are nothing at all (type is inferred, a type, ref (the foreach variable is taken by reference), const/immutable (the variable is const or immutable).

On Saturday, 9 April 2016 at 11:03:54 UTC, Nicholas Wilson wrote:
> On Saturday, 9 April 2016 at 10:56:34 UTC, Lucien wrote:
>> On Saturday, 9 April 2016 at 10:28:05 UTC, Basile B. wrote:
>>> On Saturday, 9 April 2016 at 10:10:19 UTC, Lucien wrote:
>>>> Hello.
> FYI the things that you can put there (in place of auto) are nothing at all (type is inferred, a type, ref (the foreach variable is taken by reference), const/immutable (the variable is const or immutable).

Yes, it's right that to put the type is a noop, but otherwise DCD doesn't work in foreach. Personally I think it s*c*s a lot. The manual specification of the type should be allowed.

On 4/9/16 6:10 AM, Lucien wrote:
> Hello.
>
> When I do:
>
> ---------------------
> class MyClass{..}
> class YourClass{..}
> class OurClass{..}
>
> YourClass yc = new YourClass();
>
> foreach (auto id; [ typeid(MyClass), typeid(YourClass), typeid(OurClass) ])
> {
>    if (typeid(yc) == id)
>    {
>      writeln("It works !");
>    }
> }
> ---------------------
> The compiler says: basic type expected, not auto
> Why can't I have one time the type id of MyClass, then of YourClass and
> of OurClass ?
> Is there an alternative ?

I know this is not exactly what you may be expecting, but you could do what you want this way:

import std.meta: AliasSeq;

foreach(classType; AliasSeq!(MyClass, YourClass, OurClass))
{
   // in here, classType is now an alias for the actual class
   auto id = typeid(classType); // if you want it in TypeInfo_Class form
}

This is called a static foreach.

-Steve