On Mon, 25 Feb 2013 13:36:18 -0500, Timon Gehr <[email protected]> wrote:
On 02/25/2013 05:45 PM, deadalnix wrote:
On Monday, 25 February 2013 at 16:35:52 UTC, Timon Gehr wrote:
The inout resolution of opSlice takes care of that.
You got to be more precise about what you have in mind as I see plenty
of way to make it fail (with static if for instance). I see also how it
can work in trivials cases, but we need more than that.
There is no question if it works, other languages have done a lot more
than this. It is universal quantification. (using ad-hoc syntax
elements. This is by no means how it should actually end up looking, in
the unlikely case it is actually implemented.)
It can replace inout as follows:
int foo(inout int[] x) inout;
<=>
int foo[@type_constructor cons](cons int[] x) cons;
The benefit is that it allows multiple distinct type constructor
variables, and that it works on aggregate declarations as well:
void foo[@type_constructor cons1, @type_constructor cons2](cons1 int[]
x1, out cons1 int[] y1, cons2 int[] x2, cons2 int[] y2);
struct S[@type_constructor cons]{
cons(int)[] x;
}
I do not see a less powerful mechanism that addresses the problems that
Steven wants to address.
I actually proposed this to Walter a few years ago (same concept,
different syntax). He said it was a solid proposal, and added too much
complexity for the value.
What I am trying to come up with is a simplification. I will post
sometime soon what I think will work. We definitely need something.
-Steve
