Jarrett Billingsley wrote:
I just don't think it's possible. If all classes had default ctors,
it'd be easy; is(typeof(new T)) would be false if and only if T were
abstract. But since that's not the case, I can't think of a way to
generically see if a given class type is abstract. Any ideas?
It's always a little frustrating when doing type introspection and
having to rely on weird side-effects and properties of types, when the
compiler is just keeping it in some flag or field somewhere. Sigh.
"is(T == abstract)"? :P
If you know the constructor arguments in advance, you can do something like:
static if (is (typeof (new Foo (1, "hello")))){}
Unfortunately, ParameterTupleOf!(T._ctor) doesn't work:
class AFoo {}
if (is (typeof (AFoo._ctor))) Stdout.formatln ("AFoo._ctor");
if (is (typeof (ParameterTupleOf!(AFoo._ctor)))) Stdout.formatln
("AFoo._ctor params");
// prints AFoo._ctor
_ctor is a really odd construct -- spotty support, not advertised.
