• Guillaume Piolat (35/35) Apr 06 2022 This program fails to build:
• Adam D Ruppe (29/30) Apr 06 2022 Works fine if you just use the language instead of the buggy
• Guillaume Piolat (2/32) Apr 06 2022 Thanks, it will also create less templates.
• MoonlightSentinel (3/5) Apr 07 2022 Use a frontend >= dmd 2.099, it works according to run.dlang.io.
• Guillaume Piolat (3/8) Apr 07 2022 Good to know, thanks.

Guillaume Piolat <first.last gmail.com> writes:

This program fails to build:


     import std.traits: getSymbolsByUDA;

     struct MyUDA
     {
     }

     class A
     {
          MyUDA int a;
     }

     class B : A
     {
          MyUDA int b;
     }

     void main()
     {
         alias G = getSymbolsByUDA!(B, MyUDA);
     }



Output:


     
c:\d\ldc2-1.28.0-windows-multilib\bin\..\import\std\traits.d(8933): Error:
template
     instance `AliasSeq!(b, a)` `AliasSeq!(b, a)` is nested in 
both `B` and `A`
     
c:\d\ldc2-1.28.0-windows-multilib\bin\..\import\std\traits.d(8707): Error:
template
     instance `std.traits.getSymbolsByUDAImpl!(B, MyUDA, "b", "a", 
"toString", "toHash",
     "opCmp", "opEquals", "Monitor", "factory")` error 
instantiating
     main.d(19):        instantiated from here: 
`getSymbolsByUDA!(B, MyUDA)`
     Failed: 
["c:\\d\\ldc2-1.28.0-windows-multilib\\bin\\ldmd2.exe", "-v", 
"-o-", "main.d", "-I."]


Any idea how to workaround that? I really need the same UDA in 
parent and child class.

Adam D Ruppe <destructionator gmail.com> writes:

On Wednesday, 6 April 2022 at 18:10:32 UTC, Guillaume Piolat 
wrote:
 Any idea how to workaround that?

Works fine if you just use the language instead of the buggy 
phobos wrappers:

---
     struct MyUDA
     {
     }

     class A
     {
          MyUDA int a;
     }

     class B : A
     {
          MyUDA int b;
     }

     void main()
     {
         foreach(memberName; __traits(allMembers, B))
         foreach(attr; __traits(getAttributes, __traits(getMember, 
B, memberName)))
         static if(is(attr == MyUDA))
                 pragma(msg, memberName); // a, b
     }
---

So make a function that does that and applies whatever it is you 
need to apply and you're in business.

Note that it is `is(typeof(attr) == MyUDA)` if defined 
` MyUDA(args)`.

Guillaume Piolat <first.last gmail.com> writes:

On Wednesday, 6 April 2022 at 18:21:11 UTC, Adam D Ruppe wrote:
 On Wednesday, 6 April 2022 at 18:10:32 UTC, Guillaume Piolat 
 wrote:
 Any idea how to workaround that?

 Works fine if you just use the language instead of the buggy 
 phobos wrappers:

 ---
     struct MyUDA
     {
     }

     class A
     {
          MyUDA int a;
     }

     class B : A
     {
          MyUDA int b;
     }

     void main()
     {
         foreach(memberName; __traits(allMembers, B))
         foreach(attr; __traits(getAttributes, 
 __traits(getMember, B, memberName)))
         static if(is(attr == MyUDA))
                 pragma(msg, memberName); // a, b
     }
 ---

 So make a function that does that and applies whatever it is 
 you need to apply and you're in business.

 Note that it is `is(typeof(attr) == MyUDA)` if defined 
 ` MyUDA(args)`.

Thanks, it will also create less templates.

MoonlightSentinel <moonlightsentinel disroot.org> writes:

On Wednesday, 6 April 2022 at 18:10:32 UTC, Guillaume Piolat 
wrote:
 Any idea how to workaround that? I really need the same UDA in 
 parent and child class.

Use a frontend >= dmd 2.099, it works according to run.dlang.io.

Guillaume Piolat <first.last google.com> writes:

On Thursday, 7 April 2022 at 12:56:05 UTC, MoonlightSentinel 
wrote:
 On Wednesday, 6 April 2022 at 18:10:32 UTC, Guillaume Piolat 
 wrote:
 Any idea how to workaround that? I really need the same UDA in 
 parent and child class.

 Use a frontend >= dmd 2.099, it works according to run.dlang.io.

Good to know, thanks.