One step out of the TypeInfo stalemate

[Alexandru Ermicioi]

On Saturday, 25 July 2020 at 16:34:07 UTC, Andrei Alexandrescu 
wrote:
> I think this has been attempted before. The TypeInfo* classes 
> in object.d are one gnarly thing after another:
>
> https://github.com/dlang/druntime/blob/master/src/object.d
>
> Very poor usefulness to real estate ratio, ugly and inefficient 
> implementation, etc. etc.
>
> One simple step out of this would be to replace TypeInfo_Struct 
> with a template TypeInfo(T) if (is(T == struct)).

That would make typeinfo hierarchy a lot cleaner.
Having type known in typeinfo object would also allow 
implementation of reflection methods as members which in turn 
would make reflection based code much much cleaner from developer 
perspective.

For example currently to check if member is present on type T we 
have to do smth like:

__traits(hasMember, T, "member")

When it can be more readable through typeid statement like:

typeid(T).hasMember!"member"

It would also be nice for typeinfo to provide both templates and 
non-templated alternatives for reflection operations. For example 
for hasMember it could also offer:

typeid(T).hasMember("member")

While templated methods could be used to inspect types when they 
are known at compile time, non-templated ones may be used to 
inspect entities with erased type.

But this of course is not for the first step but rather one of 
the future ones. I hope this message provided some insight on 
what can be improved regarding type info, In the future.

Best regards,
Alexandru.