Choosing arity of a template function

[Marc Schütz via Digitalmars-d]

On Friday, 26 February 2016 at 23:11:32 UTC, Andrei Alexandrescu 
wrote:
> On 02/26/2016 06:09 PM, Andrei Alexandrescu wrote:
>> static if (is(partition == function) || is(partition == 
>> delegate))
>>    partition(r);
>> else if (__traits(compiles, partition!less(r, n)))
>>    partition!less(r, n);
>> else
>>    partition!less(r);
>>
> Nevertheless, I'm still on lookout for a more elegant solution! 
> I have this mindset that using __traits(compiles) is some sort 
> of cheating.

I don't see it as cheating; in fact it is more elegant, because 
it checks for exactly the thing you depend on, namely that 
`partition` is callable. Your explicit check above rejects 
structs with opCall(), for example, which is probably not what 
you intended.