Re: [boost] [mixin] New library reminder

Subject: Re: [boost] [mixin] New library reminder
From: Borislav Stanimirov (b.stanimirov_at_[hidden])
Date: 2013-07-13 02:50:45

On 07/12/2013 06:19 PM, Larry Evans wrote:
>
>
> How could type TypeErasure library be used to attach concepts
> analogous to xml_serializer and book_data to a mixin::object
> which has been mutated as above?  (BTW, I don't see a real use for
> this; however, I'm just trying to get a better understanding of the
> relationship between the two libraries).
>
>

I don't think that's possible. TypeErasure's concepts work with template 
functions that either compile or don't compile for a specific type. The 
mixin objects in Boost.Mixin as a C++ type have almost nothing. The 
object's messages (methods) that become available when you add some 
mixins to it are dynamically bound. You cannot have compile time checks 
about the mixins that comprise an object. Only runtime checks. Calling a 
message on a boost::mixin object ALWAYS compiles. If the message is not 
available there will be a runtime error instead.

Of course you CAN have TypeErasure concepts for the actual methods of 
boost::mixin::object like `has`, `get`, `implements`, but I don't think 
that's very useful.

Since TypeErasure provides primarily compile time features, and 
Boost.Mixin provides almost exclusively runtime features, I don't think 
you can combine the power of both libraries to do something cool (like 
calling Captain Planet :D)

-- Borislav