Fully transitive const is not necessary

[Tim Burrell]

Craig Black wrote:
> The D community has been working on this problem for about a year now.  I'm 
> don't know if such a "simple effective" solution exists as you imply.  And 
> even if it does, if it takes us another year to figure it out, then that's a 
> year that we could be doing more productive things.

Working on const and working on a scheme for doing parallel programming 
are basically completely unrelated.  Yeah you may need one to do the 
other, but a means for parallel programming isn't born out of proper 
const support.

> Yes, I think the solution to scalable concurrency will probably be a systems 
> programming language that supports multiple paradigms.  D is a good 
> candidate here, being very multi-paradigm.  I still don't think writing 
> scalable multithreaded apps will ever be easy.

Definitely not.  But there are ways to make it easier.  Currently D 
employs none of these.  Const will not improve the situation.

> My suggestion would be to implement a C++-like "logical const" system using 
> the const keyword, and use the invariant keyword for Walter/Andrei's 
> transitive const.  Maybe that would give us the best of both worlds.

I think I agree with you.  I'd just really like to see this debacle 
sorted out so some real effort can be made toward D3 and the possibility 
of parallel programming support.