I get how. I don't get why. (more const stuff)

[Robert Fraser]

Steven Schveighoffer Wrote:

> const(structtype) means that the structtype itself is not const, and you
> just wasted 7 perfectly good keystrokes typing 'const()' around it since the
> structtype doesn't point anywhere.  This makes no sense to me either...

Actually, if structtype constains any pointers or class references, the things those point to will be constant. It's tail-constness, so the head (what the symbol is bound to) is not constant, but the tail (anything referenced) is.

I don't like this, but I think the "head-const" and "tail-const" concepts are here to stay in D, so start thinking of "const" as "tail-const" and "final" as "head-const," and maybe that'll make more sense.

This syntax was suggested at the conference:
const() Type var; // var is head-const, what "final Type var" means now
const(Type) var; // var is tail-const, what "const(Type) var" means now
const Type var; // all of var is const, what "final const(Type) var"
                      // mans now.

Make more sense? Not really, but it's a different way of looking at it.