On Sat, Nov 24, 2012 at 11:30 AM, Artur Skawina <[email protected]> wrote:
> On 11/24/12 08:27, Philippe Sigaud wrote:
> > What's even nicer with an is() expr is that the introspection info is
> accessible when used inside a static if. So with Artur's code, CT can be
> seen inside the true branch of the static if.
>
> Actually, static-ifs do not create a scope, so 'CT' leaks and is accessible
> after it's defined, not just inside the static-if branch:
>
You're right, I didn't think it through. Time to update my tutorial, then :)
> Unfortunately the is-expressions don't handle aliases properly, at least
> with my old compiler here. So this does not work:
>
> template isTempInst(alias TEMPL, T) {
> static if (is(T _ == TEMPL!CT, CT))
> enum isTempInst = true;
> else
> enum isTempInst = false;
> }
Works for me:
template isTempInst(alias TEMPL, T)
{
static if (is(T _ == TEMPL!CT, CT...))
enum isTempInst = true;
else
enum isTempInst = false;
}
void main()
{
Tuple!(int,string) t = tuple(1, "abc");
writeln(typeof(t).stringof);
writeln(isTempInst!(Tuple, typeof(t)));
}
(DMD 2.060)
