Generating code based on UDA

[Ali Çehreli via Digitalmars-d-learn]

On 10/25/2014 08:56 AM, Rares Pop wrote:

 > Indeed it worked. What is the rationale behind the mixin(fullName) ?

__traits(getAttributes) requires a symbol but fullName is a string. 
Mixing it in as code fulfills the requirement.

 > However, in my project the injections function, the @Inject UDA struct
 > and some other dependencies are defined in a library (libinfuse).

I am afraid it needs to be changed. :-/

 > In this format the compiler gives the undefined identifier error I was
 > mentioning in my first post.
 > "source/infuse/injector.d-mixin-148(148): Error: undefined identifier B"

I found two solutions:

a) Do not define 'attributes' at all and use __traits(getAttributes) 
directly in the foreach loop:

     foreach (attr; __traits(getAttributes, mixin(fullName))) {

b) Define attributes as a typeof of __traits(getAttributes) and use that 
in the foreach loop:

     alias attributes = typeof(__traits(getAttributes, mixin(fullName)));
     foreach (attr; attributes) {

I think what happens in both cases is that the entity that we iterate 
over maintains its TypeTuple'ness without trying to produce a value out 
of its members.

 > Is this a dmd compiler bug?

I don't know but it is very confusing.

Ali