Can I make a variable public and readonly (outside where was declared) at same time?

[AsmMan via Digitalmars-d-learn]

On Friday, 26 September 2014 at 18:18:45 UTC, Steven 
Schveighoffer wrote:
> On 9/26/14 1:36 PM, "Marc =?UTF-8?B?U2Now7x0eiI=?= 
> <schuetzm at gmx.net>" wrote:
>
>> Alternatively, you could create a union with a private and a 
>> public
>> member with the same types, but I wouldn't recommend it. 
>> Besides, the
>> members would need to have different names:
>>
>>     class Foo {
>>         union {
>>             private int a;
>>             public int b;
>>         }
>>     }
>
> Hm.. that doesn't provide readonly access to either a or b.
>
> But it gave me an idea:
>
> class Foo {
>    union {
>       private int _a;
>       public const int a;
>    }
>    void setA(int x) { _a = x; }
> }
>
> Hot damn! It works too :) Can't access _a from outside the 
> module, can access a, but can't write it (even from within 
> Foo). It's like an auto-inlined property function.
>
> I don't know how it would affect the optimizer, or the GC 
> scanner. Unions are ugly things...
>
> -Steve

This is really a loot cool and works. Thanks. If private in D had 
same behavior like in C#/C++, ie, private to scope of where class 
was declared and not public to the entire module, I guess we 
could even do:

class Foo {
	union {
		private int a_;

		public @property int a() {
			return a_;
		}

		private @property void a(int value) {
			a_ = value;
		}
	}

         //no one need knows the 'a_' (ugly?) identifier
	void setValue(int x)
	{
		a = x;
	}
}

And then

Foo f = new Foo();
f.a = 10; // give a compile error becaus it is private and 
acessible within Foo class only

BTW: I'm not sure about memory usage where using properties. But 
it is still cool.