[Issue 23278] Can't pass alias member to a function

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=23278

RazvanN <razvan.nitu1305 at gmail.com> changed:

           What    |Removed                     |Added
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                 CC|                            |razvan.nitu1305 at gmail.com

--- Comment #3 from RazvanN <razvan.nitu1305 at gmail.com> ---
(In reply to Marcelo Silva Nascimento Mancini from comment #0)
> This trivial code fails to compile with the error message: 
> `onlineapp.Test2.mxString!(oops).mxString` need `this` to access member
> `mxString`
> 
> ```d
> class Test2
> {
>     string oops;
>     mixin(mxString!(oops));
> }
> enum mxString(alias c)()
> {
>     return "";
> }
> ```
> 
> This should compile as there is no dependent usage on "this". Plus, the
> message is obviously wrong as there is no member named `mxString`.
> 
> A real use case for that is:
> ```d
> enum mxString(alias c)()
> {
>     return typeof(c).stringof~" "~c.stringof~c.stringof~";";
> }
> ```
> Which does not depends on "this", as some code like `mxString!(typeof(oops),
> oops.stringof)` would work.
> 
> Mixin template does not have this limitation, so, I believe a normal
> function should not too.

I don't really understand what you are trying to achieve here? mixin templates
are used to insert declarations in a scope. If you want to mixin a function,
why not declare mxString as:

```
class Test2
{
    string oops;
    mixin mxTempl!(oops);                                                       
}

mixin template mxTempl(alias c)
{
    enum mxString()
    {   
        return ""; 
    }   
}
```

This is an enhancement request at best. However, I don't really see the point
of this code. Why would you want to insert a publicly declared template in the
scope of an aggregate? Why not just call the function template when it is
needed with the appropriate template parameter?

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