mixin template templateUGC (
   typeStringUTF,
   alias lstrStructureID
   ) {

   public struct lstrStructureID {

      typeStringUTF whatever;

   }

}

mixin templateUGC!(string,  "gudtUGC08");
mixin templateUGC!(dstring, "gudtUGC16");
mixin templateUGC!(wstring, "gudtUGC32");

void main() {

   gudtUGC32 something; /// Error: undefined identifier `gudtUGC32`

}

I cannot manage to get this right; not even with:

   public struct mixin(lstrStructureID) { ... }

because the argument seems to require a complete statement.

On Sunday, 11 July 2021 at 05:54:48 UTC, Ali Çehreli wrote:

Yes, that I tried, but the structure has a lot of lines of codes and so it is impractical and of course it will turn out difficult to debug.

Since this seems to be a dead-end I did reshuffle some things around:

/// for illustration purposes only:
alias stringUTF08 = string;  /// = immutable(char )[];
alias stringUTF16 = dstring; /// = immutable(dchar)[];
alias stringUTF32 = wstring; /// = immutable(wchar)[];

alias stringUGC08 = gudtUGC!(stringUTF08);
alias stringUGC16 = gudtUGC!(stringUTF16);
alias stringUGC32 = gudtUGC!(stringUTF32);

public struct gudtUGC(typeStringUTF) {

   typeStringUTF whatever;

   ... lots of functions using typeStringUTF here

}

void main() {

   version (useUTF08) { stringUGC08 lugcSequence3 = stringUGC08(r"..."c); }
   version (useUTF16) { stringUGC16 lugcSequence3 = stringUGC16(r"..."d); }
   version (useUTF32) { stringUGC32 lugcSequence3 = stringUGC32(r"..."w); }

}

It works.

Thanks Ali :) !

On Sunday, 11 July 2021 at 05:20:49 UTC, someone wrote:

mixin template templateUGC (
   typeStringUTF,
   alias lstrStructureID
   ) {

   public struct lstrStructureID {

      typeStringUTF whatever;

   }

This creates a struct with teh literal name lstrStructureID. Just like any other name. So it is NOT the value of the variable.

   public struct mixin(lstrStructureID) { ... }

Indeed, you'd have to mixin the whole thing like

mixin("public struct " ~ lstrStructureId ~ " { ... } ");

On 7/11/21 8:49 AM, Adam D Ruppe wrote:

mixin template templateUGC (
   typeStringUTF,
   alias lstrStructureID
   ) {

   public struct lstrStructureID {

      typeStringUTF whatever;

   }

   public struct mixin(lstrStructureID) { ... }

when I've done this kind of stuff, what I usually do is:

struct Thing {
  ... // actual struct
}

mixin("alias ", lstrStructureID, " = Thing;");

the downside is that the actual struct name symbol will be Thing, or whatever you called it. But at least you are not writing lots of code using mixins.

-Steve

On Sunday, 11 July 2021 at 12:49:28 UTC, Adam D Ruppe wrote:

Could you explain more detail?

On Sunday, 11 July 2021 at 13:30:27 UTC, zjh wrote:

It is just normal code with a normal name. The fact there's another variable with the same name doesn't change anything.

mixin template templateUGC ( typeStringUTF, alias lstrStructureID){
   public struct lstrStructureID {
      typeStringUTF w;
   }
}
mixin templateUGC!(string,  "gudtUGC08");

You say This creates a struct with teh literal name lstrStructureID.
I tried,can compile,but I don't know generate what.

Could you explain more detail?

On Sunday, 11 July 2021 at 14:04:14 UTC, zjh wrote:

just genenrate lstrStructureID struct.

On Sunday, 11 July 2021 at 12:49:28 UTC, Adam D Ruppe wrote:

As I mentioned in my previous reply to Ali this could be viable for one-liners-or-so, but for chunks of code having, say, a couple hundred lines for one UDT, it will become debug/maintenance-hell soon ... so clearly; it is a no-go ... for my specific case at least.