Why do we have transitive const, again?

[Jonathan M Davis]

On Saturday, September 24, 2011 16:08:04 Walter Bright wrote:
> On 9/22/2011 10:36 AM, Peter Alexander wrote:
> > It's mostly for concurrent programming.
> 
> It's also for:
> 
> 2. purity
> 3. support for true functional programming
> 4. implicit & enforcable documentation on what a function may do with its
> parameters 5. better isolation and encapsulation of specific areas in a
> program

I use it for _way_ more than concurrent programming. In fact, I use it pretty 
much the exact same what that I do in C++. The difference is that you can't do 
any kind of caching or lazy loading of member variables or member function 
return values, but I _rarely_ do that anyway, so for what I do, it isn't an 
impedement at all. I think that Peter's take on it stems from the fact that 
he's work in a gaming enviroment where he cares a lot more about stuff like 
lazy loading and caching, because he needs them for performance. I would say 
thought that most domains don't need that. Some obviously do, and it would be 
nice to have with const, but when you actually care about stuff like 
__restrict, you're in a _very_ different world from your average programmer.

The biggest roadblocks that I've run into with const stem from quality of 
implementation issues, which makes it so that const is unusable in a number of 
cases where it should be (e.g. this(this) not working with const and the fact 
that object isn't const-correct). So, I can't use it as much as I would like, 
but I use it a lot.

- Jonathan m Davis