Dnia 2009-05-31, nie o godzinie 15:36 -0400, Jarrett Billingsley pisze:
> On Sun, May 31, 2009 at 3:26 PM, Witold Baryluk
> <bary...@smp.if.uj.edu.pl> wrote:
> >
> > Horrible.
> >
> > How to ensure constness of data, and still have possibility of changing
> > references of local variables?
>
> Rebindable.
>
> http://www.digitalmars.com/d/2.0/phobos/std_typecons.html#Rebindable
Thanks. I was already thinking about implementing something like this.
It is very thin, and probably doesn't eat even single byte more than
original reference.
So generally we need to cheat: union with const and non-const version +
opAssign/opDot, and some hidden casts. If everybody is doing this, why
not.
Only one problem is that i need to make some wrappers for it:
alias Rebindable!(C) CC;
first try:
auto c1 = CC(new C(1));
auto c2 = CC(new C(2, c1)); // oops doesn't work
c2 = c2.b();
second try:
auto c1 = CC(new C(1));
auto c2 = CC(new C(2, c1.opDot())); // ok, works
c2 = c2.b();
define some function on original data:
int something(in C c) {
return c.a;
}
something(c2); // oops, doesn't work
something(c2.opDot()); // ok, works
So generally now i need to overload all my functions to support also
Rebindable!(C), where I will unwrap object and call original function?
The same with constructors.
Can't be this done more simpler?
As I remember there was something like opCast (for explicit casts)?
Maybe Rebindable should have it casting to original type (with const)?
