how to call class' template constructor

[anonymous via Digitalmars-d-learn]

On Sunday, 12 October 2014 at 19:46:41 UTC, ketmar via
Digitalmars-d-learn wrote:
> Hello.
>
> please, how to call template constructor of a class? it's 
> completely
> escaped my mind. i.e. i have this class:
>
>   class A {
>     this(alias ent) (string name) {
>       ...
>     }
>   }
>
> and i want to do:
>
>   void foo () { ... }
>   auto a = new A!foo("xFn");
>
> yet compiler tells me that
>
> "template instance A!foo A is not a template declaration, it is 
> a class"

I think there's no nice way to explicitly pass template arguments
to constructors. Here's a hack:

    auto a = cast(A) (new void[__traits(classInstanceSize, 
A)]).ptr;
    a.__ctor!foo("xFn");

I didn't think this through or test it thoroughly. So it most
probably has issues. You could try to identify and fix them, and
then hide the ugly away in a function.

But the two leading underscores tell it: "__ctor" is an
implementation detail. It may disappear/change without notice.

Some other solution/workaround would probably be the better
choice. Like a static factory method that's already been
mentioned.