On 11/29/10 1:49 PM, Steven Schveighoffer wrote:
On Mon, 29 Nov 2010 14:38:40 -0500, Andrei Alexandrescu
<[email protected]> wrote:
On 11/29/10 1:35 PM, Steven Schveighoffer wrote:
On Mon, 29 Nov 2010 11:52:31 -0500, dsimcha <[email protected]> wrote:
== Quote from Andrei Alexandrescu ([email protected])'s
article
Ultimately I believe we need to make Rebindable palatable. That would
have the nice side effect of enabling other proxy types.
Andrei
I've asked before and I'll ask again, what's still wrong with
Rebindable? A bunch
of alias this issues got fixed in 2.050, and I fixed a bunch of misc.
convenience
issues a few releases ago. I fail to see the problem with it anymore.
Every few months or so, someone finds a problem with it. It seems that
it's good enough in theory, but miserably fails in practice when someone
tries to use it. I admit I haven't looked at it in a while, but there
are implicit casting problems that cannot be solved without compiler
help. I just think Rebindable will get more and more convoluted until
someone finally admits that this is better served as a builtin feature.
I don't grok this. If people find different issues with it that are
fixed, then there is progress, right? (Clearly "escaping" into the
language makes things better.)
At some point, Rebindable may be as good as a language feature. But we
haven't got there yet. And we haven't got there in years. And I don't
see us getting there in the forseeable future -- there are too many
implicit casting problems to solve.
At the point where it does become useable, how big will it be? How much
will it slow down compilation? How specialized do we have to make code?
Const is supposed to be a compile-time feature, optimized out at
runtime. If Rebindable isn't completely removed from the code
generation, then it is not a complete feature.
I don't think compilation speed and runtime speed are the main
challenges. All of Rebindable's methods are one-liners. The issue with
Rebindable is integration within the type system.
One of those issues:
import std.typecons;
class C {}
void foo(Rebindable!(const C) c)
{
}
Let me fix that:
void foo(const C c)
{
auto rc = Rebindable!(const C)(c);
...
}
You missed the point.. completely :)
please look at bar.
You're right. bar is the part that alias this needs to take care of. So
in a way this is an easier problem to solve.
Andrei
