Why are opEquals/opCmp arguments not in or const for Objects?

[Timon Gehr]

On 03/18/2013 12:19 AM, Peter Williams wrote:
> The current signatures for opCmp/opEqual mean that code like:
>
>
> bool strictly_ordered(T)(in T[] list) {
>      for (auto j = 1; j < list.length; j++) {
>          if (list[j - 1] >= list[j])
>              return false;
>      }
>      return true;
> }
>
> will fail to compile if T is a class because opCmp cannot be called with
> a const argument.  This restricts the quality of code that can be
> written by limiting legitimate use of in/const arguments to
> functions/methods.
>
> Trying to work around this problem by defining opCmp/opEquals for the
> class being used with in or const argument does not work as they are not
> recognised as an override of the Object methods.
>

Yes they are.

> So my question is "Why are the arguments to opEquals and opCmp (for
> Objects) not declared in or const?".
>

Because not all valid implementations can be. They shouldn't be in 
Object anyway.