Hi,

I loop through a structure during compile time and want to check whether a field of the structure is of type Nullable.

Therefore I use the TemplateOf traits which works for Nullable fields but raises an error for fields which are structures and not templated.

static if(is(T == struct) && __traits(isSame, TemplateOf!T, Nullable)){}
>> template std.traits.TemplateOf does not match any template declaration

I can not find a traits "isTemplateOf". Is there are workaround?

Kind regards
André

Are you looking for something like this?

import std.typecons;
import std.traits;

alias yes = Nullable!int;

struct no {}

template isNullable(T : Nullable!X, X)
{
    enum isNullable = true;
}

template isNullable(T)
{
    enum isNullable = false;
}

void main()
{
    static assert(isNullable!yes);
    static assert(!isNullable!no);
}

On 06/13/2017 02:00 AM, Andre Pany wrote:

> I can not find a traits "isTemplateOf".

You're close. :)

  https://dlang.org/phobos/std_traits.html#isInstanceOf

Ali

On Tuesday, 13 June 2017 at 09:18:47 UTC, Ali Çehreli wrote:
> On 06/13/2017 02:00 AM, Andre Pany wrote:
>
>> I can not find a traits "isTemplateOf".
>
> You're close. :)
>
>   https://dlang.org/phobos/std_traits.html#isInstanceOf
>
> Ali

Thanks :)

Kind regards
André