Getting the const-correctness of Object sorted once and for all

[Tove]

On Monday, 14 May 2012 at 16:53:24 UTC, Timon Gehr wrote:
> On 05/14/2012 06:10 AM, Chris Cain wrote:
>> On Monday, 14 May 2012 at 02:57:57 UTC, Mehrdad wrote:
>>> The problem is that it's unavoidable.
>>>
>>> i.e. you can't say "don't mark it as const if it isn't const",
>>> because, practically speaking, it's being forced onto the 
>>> programmers
>>> by the language.
>>
>> You're really against const in this language, huh?
>>
>
> I guess this is not the most important point.
> He has been trying to use const like in OO-ish C++.
> This just does not work, because D const is detrimental to OO
> principles when used that way.
> The proposal is about _enforcing_ C++-like usage of const.

but c++ has the 'mutable' keyword as an easy escape route... 
which saved me a bunch of times... guess one can emulate it with 
a library-solution using nested classes? But... what about 
structs?

class Outer
{
   int i = 6; // mutable

   class Inner {
     int y=0;

     int foo() const
     {
       // ++y; // fail
       return ++i; // look ma, mutable const
     }
   }
   Inner inner;
   this()
   {
     inner = new Inner;
   }
   alias inner this;
}