getSymbolsByUDA in constructor/member functions

[Arafel]

On 16/6/22 10:55, frame wrote:
> On Thursday, 16 June 2022 at 08:23:20 UTC, Arafel wrote:
> 
> 
> This is not true. `getMember` can return the symbol to the instance or 
> the type/alias, depending if you pass `this` or `Def`. The last is static.
> 
> It makes no sense to use the attribute from a class without an instance.
> 
> 

Classes can have static members just as structs, so I don't think you 
always need an instance for a class either.

It seems the issue could be somewhere else:

```
import std.traits: getSymbolsByUDA;

enum E;

class C {
     @E int a;
     pragma(msg, __traits(getMember,C,"a").stringof); // `a`
     void foo() {
         pragma(msg, C.stringof); // `C`
         pragma(msg, __traits(getMember,C,"a").stringof); // `this.C.a`
         // Fails here
         //static foreach (sym; getSymbolsByUDA!(C, E)) { }
     }
     // But works here
     static foreach (sym; getSymbolsByUDA!(C, E)) { }
}

```

So if you call `getMember` from a member function, it adds the hidden 
`this` reference, and this has subtle consequences later on, even if 
`this.C` is practically just an alias for `C`.

I still think this is a bug in `getMember`, although perhaps not as 
obvious as I first thought.