I have a question regarding template value parameters.

As this works:

    template B(T, T[] foo) {}

I expected

    template A(U) {}
    template B(T, A!T foo) {}

to work, too. Currently, it failes with "undefined identifier `T`".

I'm not sure as why T is undefined in this case, as the first example works properly.

In the same vein:

    alias A(U) = int;
    template B(T, A!T u) {}

This failes to compile with "undefined identifier `T`", too.

Why is this happening?

I'm using DMD v2.076.0.

On Sunday, 1 October 2017 at 08:56:52 UTC, Robin Kupper wrote:
> I have a question regarding template value parameters.
>
> As this works:
>
>     template B(T, T[] foo) {}
>
> I expected
>
>     template A(U) {}
>     template B(T, A!T foo) {}
>
> to work, too. Currently, it failes with "undefined identifier `T`".
>
> I'm not sure as why T is undefined in this case, as the first example works properly.
>
> In the same vein:
>
>     alias A(U) = int;
>     template B(T, A!T u) {}
>
> This failes to compile with "undefined identifier `T`", too.
>
> Why is this happening?
>
> I'm using DMD v2.076.0.

template B(T, alias A!T foo) {}

Note that such Q should go here https://forum.dlang.org/group/learn