Possible way to achieve lazy loading with const objects

[Christophe]

"Steven Schveighoffer" , dans le message (digitalmars.D:145415), a
 écrit :
> On Sat, 24 Sep 2011 07:19:33 -0400, Peter Alexander  
> <peter.alexander.au at gmail.com> wrote:
> 
>> I'm happy to not have logical const in D provided that the Object  
>> interface (and other similar interfaces) don't require that opEquals is  
>> const or any nonsense like that. const means physical const, and  
>> opEquals should not require physical const.
>>
>> IMO const/immutable should *only* be used when you need to pass things  
>> between threads i.e. when you *really do* need physical const. If people  
>> start using const like you would in C++ then every interface just  
>> becomes unnecessarily restrictive.
> 
> FYI, this is a bug, not a feature.
> 
> http://d.puremagic.com/issues/show_bug.cgi?id=1824
> 
> It *will* be fixed eventually.  The fact that opEquals is not const is a  
> huge problem.
> 
> -Steve

Why would it be such a huge problem, as long as there is both non-const 
and const overload ?