Dealing with raw types as attributes

[Nicholas Wilson]

On Friday, 2 November 2018 at 04:18:47 UTC, Neia Neutuladh wrote:
> On Fri, 02 Nov 2018 04:01:00 +0000, Nicholas Wilson wrote:
>> By noting that all (interesting for the purpose of UDA's i.e. 
>> not void)
>> types have a .init
>> 
>> or you could do
>> 
>> static if (is(typeof(uda) == Foo) || is(uda == Foo))
>
> Which, again, only tests for presence, when I want to check for 
> presence *and* get the value, which should be Foo.init if the 
> person supplied the raw type.

template GetMeTheValue(value...) if(value.length == 1)
{
     static if (is(typeof(value[0].init == value[0]) // A type
         enum GetMeTheValue = value[0].init;
     else
         enum GetMeTheValue = value[0];
}
...

static if (is(typeof(GetMeTheValue!uda) == Foo)