Debug help - opDispatch - unknown member function

[Dejan Lekic]

On Tuesday, 9 September 2025 at 00:40:31 UTC, Brother Bill wrote:
> https://tour.dlang.org/tour/en/gems/opdispatch-opapply
>
> This states: "Any unknown member function call to that type is 
> passed to opDispatch, passing the unknown member function's 
> name as a string template parameter."
>
> So I tried that.  But the compiler didn't like it.
> How should I play the game of passing in an unknown member 
> function name?

Hopefully this slightly modified, and commented version of your 
original code will
help you understand why your mixin is failing:

```d
import std.stdio;

void main() {
     CallLogger!C l;
     l.callA(1, 2);
     l.callB("ABC");

     // CallLogger does not have method called "callHome", but it 
has opDispatch, so
     // the compiler will lower this down to 
l.opDispatch("callHome", "foo", "bar")
     l.callHome("foo", "bar");
}

struct C {
     void callA(int i, int j) {
     }

     void callB(string s) {
     }

     // Your mixin generates code that calls C.callHome which did 
not exist
     void callHome(string a, string b) {
         writeln(a, "/", b);
     }
}

struct CallLogger(C) {
     C content;
     void opDispatch(string name, T...)(T vals) {
         writeln("called ", name);

         // Now it works, because C now has callHome method
         mixin("content." ~ name)(vals);
     }
}
```