This Week in D #37 - forum tutorials and tip on using UDAs

[Adam D. Ruppe via Digitalmars-d-announce]

On Tuesday, 29 September 2015 at 07:09:35 UTC, Jacob Carlborg 
wrote:
> This looks pretty cool. Unfortunately the original code needs 
> to be contained inside a template :( .

Yeah. You could put it in a module too (my original plan was to 
write about "module mything_impl; code here" and "module mything; 
mixin magic_from_mything_impl;" but there's a bit more difficulty 
with that and forwarding all members you don't want to transform.

Though, I just had an idea on how that might be simplified.... 
don't recreate them, just alias them!



So, conceptually, you'd do something like:


template transformer(alias member) {
     static if(hasUDA!(member, thing))
         mixin(transformed_version_of_member());
     else
         alias member = member;
}
mixin staticMap!(AllMembers!impl_module, transformer);



So you bring in the original thing via alias in much the same way 
I brought it in via template mixin, then do the rest basically 
the same.


That *should* work and not even be all that much more code. Then 
you don't need to wrap anymore. Though it does still need to be 
in a separate something, whether input module or struct, from the 
output.