comma inside is expression

[Philippe Sigaud]

On Thu, Mar 15, 2012 at 03:34, Jos van Uden <user at domain.invalid> wrote:
> I've been reading the tutorial on templates and found this example:
>
> template rank(T)  {
>    static if (is(T t == U[], U)) // is T an array of U, for some type U?
>        enum rank = 1 + rank!(U); // then let’s recurse down.
>    else
>        enum rank = 0; // Base case, ending the recursion.
> }
>
>
> TDPL never mentions the use of a comma operator inside an is
> expression. Is this an undocumented feature? Also the symbol
> 't' is never used, but if I remove it, it won't compile.
>
> It's a really good tutorial, but I find this particular example
> puzzling.

Yes, the is() expression is puzzling in general. In fact, I
rediscovered how quirky it was when writing the tutorial :)

Nathan already gave you a link.  I give it at the beginning of A.1,
but I can see it's not really visible.

I should change the link instruction to display the link as a footnote also.