[boost] Checking interest: reflectable types

Subject: [boost] Checking interest: reflectable types
From: Noah Roberts (roberts.noah_at_[hidden])
Date: 2011-04-27 12:41:53

In my work I've developed a sort of reflection library for C++.  There 
are still many problems to solve before it could near real reflection 
but I don't believe they are insoluble.  It works much like fusion maps 
except that you can extend them through inheritance.  In fact, my 
current implementation uses fusion to do its thing and with some minor 
changes to fusion::map it could provide the base.

There is a boost.reflection proposal out there that is meant to work 
with boost.extension.  This one is a bit different in that you're not 
additionally defining data; instead you declare your reflection as you 
declare your reflectable type through the instantiation of and 
inheritance from template metafunctions.

It's primarily a static/compile-time kind of reflection but can be 
extended into runtime simply by making your field types a little 
smarter.  Fields describe the data and provide access identifiers. 
Since they are general types that simply have to have an internal 
typedef you can attach whatever information is useful.  We've done such 
things as attach valid value ranges, labels, etc...

I currently use it do auto-construct property trees for user editing.  I 
plan to use it for scripting/extension.  I've had a look at boost.python 
and it looks like it would be possible, without too much difficulty, to 
automate python exposure of these types.  A coworker with 0 experience 
in metaprogramming found it fairly easy to feed the types into a 
structure meant for a report design and printing library.

This isn't a promise to actually do anything.  I'm just gauging how 
much, if any interest there is to decide if I want to go to the trouble 
of hobby developing a publicly available and usable version.