I just got it! (invariant/const)

[Steven Schveighoffer]

"Janice Caron" wrote
> On 09/04/2008, Steven Schveighoffer wrote:
>>  class C
>>  {
>>     int *m;
>>     invariant(int *) i;
>>  }
>>
>>  pure int getI(C c)
>>  {
>>     return *i;
>>  }
>>
>>  There may be a reason to use i, but not m in a pure function.  Why 
>> should
>>  pure restrict this?  It's technically correct and statically verifiable.
>
> Except that there's no way to initialise i.
>
> My understanding of the whole raw vs cooked thing in
> accu-functional.pdf is that it's a way of making an entirely invariant
> class. There would still be no way to create a class with some members
> invariant and others not, except for those that can be initialised at
> compile time.

I think this is a limitation that should be lifted, as there may be reasons 
to have an invariant member of a class that is set upon construction.  I 
can't see any reason to disallow it.

-Steve