Something like ADL from C++?

[Richard (Rikki) Andrew Cattermole]

On 06/12/2024 10:46 PM, Arafel wrote:
> On 6/12/24 9:05, Richard (Rikki) Andrew Cattermole wrote:
>> I'm fully aware of template this parameters, I was trying to get them 
>> to work 10 years ago.
>>
>> They have problems that prevent their usage.
>>
>> 1. They are templates, so not in vtable
>> 2. They require the this pointer to be typed to the child (extremely 
>> easy for this to not be the case, see 1)
>> 3. Because they are not virtual, you cannot up cast (see 2)
>> 4. Cannot be over ridden for any manual behavior
>>
>> All and all, they become very complex for common usage, quite fragile 
>> if you don't use them right, not the kind of thing you recommend to 
>> people who are use to runtime reflection.
> 
> That's true, I found a workaround using constructors and registering 
> classes there, but currently it only works with one level of inheritance 
> (without user intervention, the whole purpose of it):

Yes, once you have a level in the hierarchy that adds a constructor, you 
basically lose the ability to call that constructor with the template 
this parameter.

Which means the user derived type has to be final.

A struct starts to look inviting with all these issues present in 
classes lol