const(X) member of Y

[Dan]

On Wednesday, 6 February 2013 at 20:30:40 UTC, Maxim Fomin wrote:
> The fact that bar() does not work and (&bar)() works is 
> terrific.

Sorry - but I don't understand what is terrific? Is this sarcasm?

struct X {
   this(this) { c = c.dup; }
   char c[];
}

(1) What is special about 'struct Y { const(X) x; }' versus 'void 
goo(const(X) x) {}'?
     Both require a copy of X, but for some reason the 'struct Y { 
const(X) x; }' requires the postblit to have signature 
'this(this) const {...}'.
     Why is this?

(2) Do structs have, or is it planned that structs will have, 
true copy constructors (as opposed to postblits)?

(3) I know there have been threads on postblits and const types...
     Here is one:
     
http://forum.dlang.org/thread/CAFDvkcvvL8GxHQB=Rw9pTm-uxOKzNGVQNDv9w5Os3SkQCc=DLQ@mail.gmail.com
     and from it:

    > Qualified postblits make no sense, given that if
    > the object is const or immutable, you _can't_
    > alter it without violating the type system. But
    > without them, you can't copy const or immutable
    > objects which require a postblit.  Walter and
    > Andrei have stated in the past that they had a
    > plan for solving this, but AFAIK, they've never
    > actually revealed what it is. My best guess would
    > be to introduce copy constructors for const and
    > immutable objects, but I don't know. Regardless,
    > this is a situation that definitely needs to be
    > clarified and properly sorted out.
    >
    > - Jonathan M Davis

     Can someone summarize where this stands?
     Is the general thinking that everything is fine now?