• Elmar (44/44) Sep 27 2021 Hello D people,

Elmar <chrehme gmx.de> writes:

Hello D people,

from time to time I stumble upon the problem that methods don't 
support `alias` parameters. The compiler will emit a complaint 
which is probably also cryptic for beginners. (Including 
references/links for further reading or explanation in compiler 
error messages would be good, but offtopic.)

I remember the reason for deprecation was that GCC and LDC have 
problems supporting more than one frame for a function because of 
their code base.

I solve this conflict for myself this way:

```D
private int myStaticMethod(T, alias var)()
{
     with(T)
     {
         // do something
     }
}

struct S
{
     // other things

     static alias myStaticMethod(alias var) = 
.myStaticMethod!(typeof(this), var);
}
```

This is pretty much boilerplate stuff and not intuitive to 
understand. I catched myself mis-refactoring it two times.

D doesn't support this at the moment, right? Couldn't the 
compiler narrow this snippet

```D
struct S {
     static int myStaticMethod(alias var)() { ... }
}
```

to the above? Likewise for non-static methods.

What problems would this solution incur compared to deprecating 
it?

Or is it rather, that UDAs for methods are so unimportant for 
many cases so that we shouldn't care?

I admit I only use it for safety reasons as a double check to 
only allow explicitly attributed variables as method arguments 
(which also should be better to read).

But there are advantages of having it as method instead of global 
function.