std.concurrency and immutable

[Dicebot]

By the way this works:

import std.stdio;
import std.concurrency;

class A
{
     this() immutable {}

     // this line
     string toString() const { return "aaa"; }
}

But it will still fail if you try to receive by class type 
explicitly instead of Variant.


std.parallelism is much more mature in my opinion, but 
std.concurrency is mostly broken when it comes to qualifiers and 
needs some serious bug-fixing rampage.