Introspection - how?

[HOSOKAWA Kenchi]

Vincent Wrote:

> Hello, guys!
> I have a question related D's introspection. I try to solve serialization task (implementing JSON protocol)
> and stuck at very start: getting all class' fields with types, names and values. Just test code:
> 
>     Thread d;
>     foreach(mi; d.classinfo.getMembers(null))
> 13:     writefln(mi.name);
> 
> test.d(13): Error: function object.MemberInfo.name () does not match parameter types ()
> test.d(13): Error: mi.name can only be called on a mutable object, not const(MemberInfo)
> 
> I'm confused with such strange error: what is a problem with using MemberInfo? I just try to GET info, not WRITE!
> Anybody have idea how to get info about members? (see task above)
> Thanks.


We face related problem; classinfo mutability.
my post is article_id=90722.
I have noticed that classinfo relates core of D's class system.

http://www.digitalmars.com/d/2.0/phobos/object.html
A pointer to this appears as the first entry in the class's vtbl[]. 

It seems that this problem must be treated carefully.