how to tell if a thing is a template

[John Colvin via Digitalmars-d-learn]

On Sunday, 24 August 2014 at 00:41:36 UTC, Ellery Newcomer wrote:
> Can't think off the top of my head how you do this
>
> template IsTemplate(alias t) {
>  ??
> }
>
> static assert(IsTemplate!IsTemplate)

__traits(compiles, is(t!X, X...))

should do it, or something similar.