So I've run into an expression I need to be able to implement std.simd properly for GDC/LDC.

Doesn't work:
  @attribute("target", T) void func(string T)(...);

In this case, currently, the UDA can't receive the template arg that was given to the function.

I require that attributes on templates be able to make use of the template args, since the template arg given may affect the attribute in some circumstances.