[phobos] Improving std.signals

[Johannes Pfau]

On Sun, 2011-01-02 at 20:01 -0600, Andrei Alexandrescu wrote:
> Hi Johannes,
> 
> 
> The code looks very promising. Could you please generate documentation 
> from it and make a proposal to digitalmars.d?
> 
> 

I just generated the documentation but I noticed lastest phobos(or dmd,
I'm not sure) completely broke the code. Very simple test case:
---------------------------------------
import std.container;
void main()
{
    SList!(bool delegate(int)) handlers;
}
---------------------------------------
Results in a long list of const-related errors. Adding const to the
delegate type also isn't possible because of 
http://d.puremagic.com/issues/show_bug.cgi?id=5193
So there's no way to create a SList of delegates right now and the
signals implementation can't work without that.
I guess the review should wait until that problem is fixed?

BTW: The signals code also needs this issue fixed:
http://d.puremagic.com/issues/show_bug.cgi?id=5011
It's a very simple fix, details are in the bug report.