Pop quiz, what does this do?

[Stefan Koch]

On Wednesday, 3 March 2021 at 16:31:53 UTC, Stefan Koch wrote:
> On Wednesday, 3 March 2021 at 16:06:48 UTC, Steven 
> Schveighoffer wrote:
>> The FieldNameTuple from std.traits returns a tuple of names of 
>> all the fields that are present on a type instance.
>>
>> What about the result on things that can't have fields?
>>
>> import std.traits;
>>
>> interface I
>> {
>>    int foo();
>> }
>>
>> pragma(msg, FieldNameTuple!I);
>>
>> Without looking up the docs, or trying it, what do you think 
>> it does?
>>
>> -Steve
>
> My feeling is that it returns tuple("foo").
> But based on the name that probably shouldn't happen.

Huh ... it works as it should in this case.
Pleasant surprise :)